Historic coal fireplace to RMH conversion

I live in a town that was built up in the heyday of coal, and the house I'm moving into has a coal fireplace in pretty much every room. My understanding is that coal chimneys are designed differently from wood-fire chimneys because of the differences in the burn - namely, that coal tends to burn more completely (and at a higher temperature) leaving no creosote. This poses a problem, I understand, with burning wood in these fireplaces because coal fireplaces are (1) often unlined and (2) far narrower.

But, hang on - burns hotter? No creosote? It *sounds* like a coal chimney would be perfect for venting a rocket mass heater, right?

So my questions are twofold: First, could a coal chimney be used safely and effectively to vent a rocket mass heater? Second, could a rocket mass heater be designed to preserve the historical character of coal fireplaces in an historic home?

My idea for design is like this: Move the original mantle and hearth face a foot or so further into the room, build a (plastered brick?) stratification chamber between it and the chimney. The idea would be to load the coal basket with wood, batch-box-style; the fire would burn upward in the normal fashion, turn back 90 degrees and then up 90 degrees; up through the insulated burn stack; and then down the stratification chamber and out the chimney.

My hope is that my doing this successfully I can make this technology more accessible to those whose homes have an historical character they want to preserve, like mine. I also feel that this technology is more in keeping with the spirit of these coal fireplaces than leaving them merely decorative.

Thoughts? I can sketch something and add it later to help with visualization.

Hi Mason;
This all hinges on the size and condition of the chimney.
First, we would need to know the diameter of the coal chimney.
Then, if it is large enough, you would want a visual inspection of its condition.
As far as retaining the vintage look, that might be difficult.
Hard to say without photos and measurements.
It will certainly be a challenge for sure!

There is a lot to learn about the different RMH designs and construction principles.
But most importantly, Batchboxes and all RMHs must be built to specifications!  (Changing them will void the warranty...)
If you try to modify one, it will not work properly.
If it does not burn hot enough at the core, you will produce excess ash and most likely creosote as well.
This will lead to increasingly poor performance.  
You would not be happy.