[VAC] flash water heater installations?

[JamesArakaki@xxxxxxx]

Hi all,
   I guess my trailer ('61 vintage, about 22' long) had an odd water heater.  
Sounds like most of you  have ones similar to the Bowman.  The water heater 
compartment on mine is tall and skinny-  22-1/2" tall, 9" wide, and 10-1/2" 
deep.
   When I finally got a key made for the compartment door,  I discovered that 
it was MISSING.
   I was told that it was probably a Victor flash heater, which I can find no 
data on. I found that the Aquastar 38B propane flash heater is the closest 
fit, but even that is slightly too big.  I may not have a choice but to start 
bending and cutting metal.  I really want to keep the original door and 
exhaust vent (cool looking, 3 stainless steel dished rings like the one for 
the furnace).

   Any ideas? Anyone have a dead unit that I could rebuild?

    What DOES fit in the compartment is one of those old stainless steel 
soda/acid/water fire extingishers. I am thinking that I could MAKE a water 
heater using a pilot and thermostat from a modern unit, and braze a flame 
tube and pressure safety valve into the fire extinguisher body. The 
extinguisher tank is pressure rated to about 300 psi. This would be a regular 
water heater, with a storage tank...(sigh). 
    It would work, but I wonder if it would be legal...

-jimmy