Mixed up Maxima Squash (photos please)

I'm new to winter squashes, but have done a lot of self-education the past few weeks.  I've decided to focus my curiosity on Cucurbita Maxima, and "mix things up".  By that, I mean to plant seeds from field grown/open pollinated squash of known mothers, but unknown fathers.  Some may be true to type or self pollinated, but I imagine most will be pollinated from random maxima species labled as "Heirloom Pumpkins" or "Fall Decor"  I know some folks have started grex's or landraces in the past, but I'm curious to see photos of any crossed maximas that anyone out there has grown to maturity/harvest?  The list of known mothers that I have are below:

Rouge Vif D'Etampes Pumpkin (large red squatty)
White Flat Boer Ford Pumpkin (large flat & white)
Jarrahdale Pumpkin (boxy stout blue/grey pumpkin)
Candy Roaster Squash (long cylindrical tan with blue tip)
Golden Hubbard (red hubbard type 6 lbs)
Blue Hubbard (smaller 5ish lbs)

Possibly crossing squash

Here's an example. The hybrid tastes better than either parent.

Here's another example.

Thanks for the examples Joseph!  Very helpful.

I already have more squash seeds than I can grow, but I'll try...I just bought 3 more mixed Maximas.  Looking over the available squash, I could see traits with a fair number of them that indicated clear multi generation cross pollination.    Some had Hubbard influence, Turban, cupping, various heirloom "pumpkin" squash influence, etc.  I was half tempted to offer a price on the whole lot, but I don't think they are desperate enough yet with Thanksgiving on the horizon.  They did finally mark them down in price a bit, so thought I'd pick a few out of the lot in case I missed them.  Two of the three I chose were very similar in form.  They were the reddish/green color of a Golden Hubbard, but large ovoid shape with shallow pumpkin type ribbing.  The 3rd one looks like a blue Jarrahdale, but the blossom end terminated in a bulbous point like an acorn rather than concave like a typical pumpkin type.  All 3 ranged from 16-18.25 pounds.  See pics below.  

I'm not sure yet what phenotype I want to eventually work toward, but some of the things that I think are important are longevity in storage, flavor/texture, dense fruit with small seed cavity compared to edible flesh.  I like the hard skin for protection, and have so far avoided turban/cup types, because I read they don't keep as long due to the bottom seam.  Though I'm sure there is a strong chance the pollen of those types got in there, I can select away from it.  I tried to find ones that felt heavy for their size with the thinking that they were more densely filled.

Is there a shape or size that is easier to store or lasts longer in storage?  

Is bumpy or peanut type skin more prone to harbor shelf-life shortening bacteria or fungus than smooth skin?

Are smaller squash genetically likely to produce smaller squash, or could they be the end of season "runts" of the larger varieties?

What are some preferred reasons to choose a small, medium, or large squash line to breed?  Meaning, why would someone want to breed for a mid-size squash rather than a larger one?  I imagine like anything, it's subjective to the cook's preferences, storage space, strength, etc.  But is there something more to it?  Like does the texture of larger squash suffer where small-medium size is better?

Upon closer inspection of the two similar red squash in the above photo, one clearly has the maxima type dry rope looking stem. The other however, has an angular flat 5-side stem, which to my understanding is not entirely maxima. Could it be a cross of golden hubbard x Dickinson field moschata? As mentioned above, it has the skin color/texture of golden hubbard but with pumpkin shape/slight ribbing. Looking at the two side by side, you'd think they came off the same vine... except for the stem.  

Edited to add:  I was just reading an interesting report that confirms maxima & moschata can cross & typically produce maxima looking fruit with moschata looking vines. The seeds may be sterile if only self pollinated, but if pollinated with another maxima, they'll be fertile if I understand correctly. This sounds like seedless watermelons needing a pollinator to fruit.  I may just plant many seeds from this cross & add a pollinator to see what happens. Something to sleep on at least...

I read in another post somewhere that Joseph Lofthouse once had a Maxima x Moschata cross, but the seeds it contained didn't germinate.  However, I read in another report of a commercial Maxima x Moschata cross that was stabilized.  Was this just the right combination of genes?  If you read this Joseph, do you have any ideas about this?  I remember you mentioning before about a creolized landrace, but don't recall the details.

I'm planning to cut into this one on Thursday, and if there's any interest, I'll get some photos & post anything of significance.  I'm not sure if it will even contain seeds, but if it does, what do you think I should do with them?  

Should I grow them in isolation & take a chance on self pollination to concentrate the strain as in line breeding?  

Should I grow them with the other nearly identical Maxima from the same photo as a pollinator in case they are like a seedless watermelon that will produce vine/flowers, but not the pollen to self-fertilize?  

I'm open to ideas since I wasn't expecting an inter-species hybrid when I bought it, but am excited to learn more about such a rare occurrence.  

A lot of great things can happen in a garden, when we take the time to actually see what is happening.

I found 1 naturally occurring [maxima X moschata] hybrid in a decade of growing thousands of  the parent species close together. Tetsukabuto is a commercially available interspecies hybrid. It's an F1 hybrid, therefore, not at all stable. The male flowers wither away before developing pollen.

Yes! That's the commercial hybrid I read about. Now that you mention it, I remember that it WAS an F1 & not a stable cross.   I think I've been reading so much, I got mixed up on the repeatable aspect rather than stability.  So, it seems to me, that if I get seeds, they aren't likely to germinate.  However,  if they do,  then I should have an additional pollinator at the ready. We'll see what happens, the worst thing that could happen is nothing germinates.  Thanks for clarifying my understanding Joseph...much appreciated.

Well, the hybrid that I was so excited about was very disappointing once I cut into it. The interior was entirely stringy like a spaghetti squash,  but with the golden hubbard exterior.  I'm not even going to save the seeds from this one.

The blue jarrahdale one pictured above (top & bottom) had like an inner hardened area in between the layers of cooked flesh. If you look at the opened pumpkin here, you can see it as a whitish color.

The blue hubbard wasn't cured as long as the golden hubbard was, but the golden hubbard cooked up dry, orange, & creamy.

I found this giant white maxima at the dump,  but didn't cook it. It wasn't orange fleshed. I'm not sure if more age would've mattered,  but it was probably 50 pounds.