I just purchased my second fridge and a few other appliances (water heater, stove, toilet) from Palomino Parts and have been thoroughly pleased with price and service. You need to know the dimensions/part number of what you want, although they are knowledgeable. On my last transaction (3 days ago), Jevin told me that they have a surplus of RM2620s that are going really cheap. Check the dimensions and see if it will work for you. (It's a little shorter and narrower than the big 2820) You won't beat the price, I'm pretty sure of that. (The RM 2820 was $800 + shipping) (Tell Jevin Ron sent you. I won't get anything out of it, but it'll make him feel good.)
As for replacing, I don't know what a '65 is like, but for the '72, it wasn't difficult once I realized I had to disassemble half the kitchen. (Well, maybe not half, but certainly part of.) The key with anything in an Airstream is to realize that you're going to have to remove walls, cabinets, etc. to get to the part you want to remove. This is where a shop manual (which I don't have) would come in really handy.
I will be installing my second 2820 in the '73 Sovereign
I'm working on in the next 2 weeks and I'll take some pics. (I can also take some pics of the empty cavity which is identical to my '72 Overlander to show you where the hold down brackets were. Of course, it's probably different in yours!)
Now, my input on new refrigerators....
I should have junked the original when I purchased the trailer last year (Overlander). The new Dometic RM2820 is beautiful!! It has a light inside!! It has a 12v
connection (for controls only) that automatically selects between gas and 110v AC. No Rust!! It gets cold fast!! It has more room!!!
I can't believe I waited so long!!!
PM me if you have any questions.