I also found this gasket sheet material that used to under high heat conditions such as found with pellet and wood stoves.
https://www.amazon.com/Universal-Pel...ywords=Lytherm
I need first need to reassemble and connect the furnace to regulated gas and 12 Volts so to test it outside the RV.
The service manual
http://bryantrv.com/docs2/docs/FA7200.pdf
There is a section in the service manuals diagnostics
"Blower runs but burner does not light"
What I've observed so far is the blower comes but the burner doesn't light.
When this happens, the service manual list 14 things to check and test for the 7600 series.
The manual also has wiring diagrams and other information to help diagnose and troubleshoot.
So after some further testing and figuring in more detail it's operations, hopefully I'll be able to narrow down the problem of no heat output.