It should be an Atwood Hydro Flame - Probably a 8516-II - at least that is what my '93 has.
If you need parts all the 8500 series use very similar parts. I was able to walk into my local RV place and get an ignitor and circuit board off the shelf.
The first thing I would do is have the circuit board checked by an RV place. I had mine checked at Curtis Trailer in Hillsboro, but any large place should have the test machine, they didn't charge me anything and it only took 2 minutes. You can pop it out of the furnace in just a few minutes. It is only held in by a wing nut. No need to take the entire furnace out or take the camper to the RV place.
I ended up needing a new board and went with a Dinosaur brand board made right here in our own Lincoln City. Plugged it in, and the furnace took off like a champ!!
If you open the outside door it 'should' have the instructions, model info and circuit layout on the inside.
Good luck!
If you need an extra ignitor, I'm pretty sure I have a spare that works....