Anyone know Brunner air compressors?

[miller]

What I've got is a upright Brunner, probably a 50-60 gal tank. If it makes any dif, I'll look up numbers.

Tried finding a manual, or something, on the beast...but no go. It does go. Thing is bullet-proof.

Question is, what the oil level should be? And, where do you add oil at? Can't find anything on either.
No sightglass, no dip stick, no way to tell.

Any ideas?

 

[miller]

Found the answer.

Got a Brunner 320. Appears there should be a short standpipe/sightglass, that's also used as the oil fill. Where it should be, has a plug in it.