Based on that Atwood part number and year of your RV I suspect you have a GC10A-4E or GCH10A-4E (if you have motoraid)
Never dealt with this place but they list 16 in stock
https://master.plumbshops.com/produc...water-heaters/
Atwood parts (water heaters/furnaces_ are getting hard to find
Dometic has their own water heater/furnaces designs and have dropped support for Atwood products