My wife found this yesterday on Craigslist.
http://grandrapids.craigslist.org/for/1129541262.html
It is the exact same model
furnace as in our 1978
Trillium 1300. I considered it, but I found out from a local RV service center that repair parts are no longer available for this model (much as I expected), so I'd rather get a replacement heater that can be repaired later on. Perhaps someone else with a 70's era egg would love to have it.