Inherited Schramm Air Compressor - Need Help

[Kuhns_Toys]

Hi All,
I recently inherited a Schramm air compressor. Our father was going to fully refurbish this machine before he unexpectedly passed. We intend on selling it, but want to find the right home for it. We don't just want it to end up at someone's garage, getting used to it's death. I know very little about the compressor. I just bought a new battery and when I turn the key, the engine turns freely and air builds up immediately. I don't even know if it takes unleaded or diesel. It's been sitting for about 5 years. (Dad broke his hip and wasn't able to move around much the last few years).
Thanks in advance to all the information. I'm new to this forum and will do my best to provide the requested info and to reply.
Please feel free to offer any advise or comments.
Here are a few pictures: