1973 Holiday Rambler travel trailer

Hello for him, I was directed here buy another form user about questions I have to anyone that knows anything about 1973 holiday Ramblers. My wife and I acquired it two years ago the first year we didn't get much use out of it last year we had a ton of use out of it. It is stationary up on blocks but is in very good shape. It isn't a can't round in northwest Ohio on a lake and it is beautiful. We have no intentions of moving it so I don't need to worry about tires or nothing right now. The Integrity of the camper is beautiful. I do not know the footage off hand. But I will get that when I go up there next weekend. I never got an owners manual I know it has a Dometic refrigerator I believe model rm2310. I do not have to worry about a holding tank for freshwater since we have a hook up there at the campground all the time. I know 1973 a grey water tank was optional we do not have that option all we have is a black water tank so I have it hooked up to a blue boy. So if there's anyone in here that knows anything about Dometic refrigerators I need to replace the seal on the freezer door, which I have found for sale online but I have a few questions about it before I purchase it. Also when I bought the trailer previous owner said the furnace was the only thing that really didn't work on it and I asked him what was wrong with it and he didn't know because it never worked for him. I'd like to know where the furnace is located on my Holiday Rambler and get working on that also. So if anyone has any information or knows anything about those travel trailers please let me know.