It’s a 160l compressor with the air tank badged Draper. Motor badged Red Devil, but no markings on the compressor.
Motor spins up fine, but the actual compressor is in pieces. It was given to him like that as apparently the valves on the head are leaking. Replacing them looks doable with some spring steel, but I need some other parts (gasket kit, woodruff key) that would be a lot easier if I know what it was!
My compressor uses the finger flappy valves, they are a spingy stainless and they do break sometimes, but the current ones have been in use since ~1990. I wouldn’t go sanding them down, more likely to break. Mine are Ingersol Rand finger valves and are easy to buy.
If I needed a head gasket I would try something like Klinger C4400, If you have gasketmaker near you they have lots of scraps.
Woodruff key, you cut them from a bit of round bar.