1974 24' motorhome questions

[diver]

Hi, I'm new here and have really enjoyed all this information. Thanks for that. I just bought a 1974 Argosy 24' with the 454 engine. This thing needs a lot of help, but I'm not familiar with much on this unit. There is a square box up front by the right steering arms and it has a three prong plug in. I'm not sure if it is a block heater or if it is an aftermarket piece or what it is. I thought a block heater attached to one of the freeze plugs. I'll have to investigate further, but just wondered if there was a block heater accessory for this. Also, can anyone tell me what Chevy body this is when I look for parts. There are rubber air bags inside the springs and know for sure they are bad. What do I replace these with? Do you have to replace them, or can you use something different. I'm a retired woman working on this, so be gentle with me. I'm a boat mechanic, and boats don't have steering rods or springs, but I am pretty good with engines. The marine industry used the 454 on the older boats, so I'm familiar with that anyway! Also, one quick question. The windows by the driver and passenger side, the track for sliding these is damaged, do I have to take the windows out to replace these things? What are they called. I looked on the search for window help and I don't know if it is a fuzzy or what. And if you replace these windows, do you drill out the inside rivets? is that a trim ring on the inside? I am really confused on all the window jargon and what these windows are called. The motorhome is in miserable shape, and needs some help. The engine and transmission are strong, and the body isn't that bad. Everything else is, whoa..... what have I gotten myself into. Thanks for any help here. Gayle