an old quilt: how much effort to make it usable?

I have a lot of family quilts....most in great shape with intricate patterns, tiny stitches and some, because we used them growing up a bit more worn, like the one my aunt made from my dresses that I used and used and even took to college...it's still a usable quilt for a single person.

The one I'm trying to decide what to do about is a thrift store find that I love...such a hodgepodge of pattern and color and all hand stitched in not so tiny stitches....just a heartfelt piece of work.  I think many of the pieces are flour sack prints...

The problem is the cotton batting has become very lumpy, almost pebbly, not soft and even anymore at all.

I can't decide if I would regret unstitching the top from the bottom...removing the lumpy cotton and then adding a thin cotton blanket or flannel sheet between the top and bottom before hand quilting in the same manner as originally done?

I guess I'm hesitating because once begun I've committed to the whole project...and will the quilt lose it's charm by my interference?

I usually try to pick up a hot weather project to do indoors on those summer afternoons when I don't go outside....this is one choice.

I've had it sitting around for several years now already in my undecisiveness.

Thoughts?

It seems to me that just adding a new back with new cotton fill might work.

After attaching the new backing and cotton, the whole piece would need to be "tatted" (may not be the right work) or attached every so often (as the original was).

thanks Anne!
that's about what I was thinking although I want to separate the front and back and remove thhe old cotton fill.
I like a thinner quilt and probably wouldn't want to spend what new cotton batting might cost.  I've used a thin cotton fabric for fill before and it feels nice for a light weight quilt.

I think the reason the cotton fill in this quilt matted and got lumpy was because the rows of quilting to attach the front, fill and back of the quilt were pretty far apart...also I suspect it was machine washed, as I do my old quilts occasionally but the quilting on them is quite close.