I have never heard of one but it wouldn't take much to weld one up.
I made the woodstove I use to heat this house.
The doors are the hardest part.
I got a set of doors off and old wood stove someone had thrown away.
There are problems though.
1...You would need a large hole in the roof for the chimney.
2...Woodstoves send burning embers out the chimney and they start things on
fire....like your RV's roof. (or the guy next door's roof)
3...To be safe you would need to extend your chimney about 5 feet above your
roof.
This would involve putting the chimney up when you stopped and taking it
down when you leave. You would also have to store the chimney
section/sections when you travel. They smell and have creosote in them which
will drip out.
4...They weigh a lot.
5...You would have to carry wood with you and wood is heavy.

I haven't but, if there was one, my late mother would have found it.  
Considering the sheer weight of what they took along on their travels,
including her "rock and anvil" collection (Mom, a 7/12 snowbird, had a
propensity to pack HEAVILY, not lightly), it always amazed me that they didn't
lose MORE tires on their rigs than they did.

I have worked outdoors for YEARS.  As such, I am particularly averse to the
effort required to PROPERLY use and maintain a wood-burning system in the
home, much less when camping.

As a camper whose desire is LESS hassle, not more, I recently converted to a
smokeless campfire:  I bought a two-headed "Mr. Heater" that attaches to a
20-lb propane tank.

<http://www.mrheater.com/productdetail.asp?id=676&cid=1>

Of course, I bought it at a farm supply store so I image the device is used
more for other, more productive, purposes.

Anyway, I have broken new ground with this device:  The days of a toasty warm
frontside facing the campfire while trying to ignore a freezing cold backside
are now OVER using this heater!!  This thing radiates and even directs its
heat surprisingly well.

<http://static.flickr.com/42/252939545_ba2c4466da_b.jpg>

[Sappy Grandpa mode: ON]  Here is the image of my youngest daughter with HER
youngest child.  At only 19-months, this was Kaitlyn's first campout.  We had
a GREAT time!

<http://static.flickr.com/104/252938884_c5a781e7ec_b.jpg>

<http://www.redelfs.com>

 Yes, the ones made (also) to boats, see
http://www.marinestove.com/sproductinfo.htm

Wood burning stoves/water heaters/cookers are pretty much standard up north
(roads get snowed in and you can't go to places to get propane).. They even
make wood burners for fixed places (I had a wood burning boiler for heat and
a hot tub in northern idaho)...