Just an old stove? If you want to make a cheap stove, use the can from your can food. This is what I did when I was poor. Poke holes about an inch from the bottom and cut 2 slats near the top. Fuel, your choice, camp fuel, gas, everclear, etc I got mine to boil 16 oz of water in less than 4 min.
Rural hardware stores, or specialty wood fireplace stores, may sell a small door only, for mounting on a small steel drum or large steel bucket and lid for food storage.
I have seen them, and a 3" damper for the small diameter stovepipe.
I put the 3" damper and small diameter stove pipe on a Wilderness stove, sold by a farm tool supply catelogue under a different name and for a lot less cost. I got a double wall thru for the roof. I cut the hole with a hole saw on a drill. I put a nice spark arrestor on top.
The heater stove I have is more than adequate for a 15Lx8Wx9H "hunter" trailer.
The 55 gal steel drum stove is too much stove, for a small shelter.
These shephard's stove style stoves have different sizes.