A.C. oil question.

[Tinker]

I am finally getting around to getting the ACC system in my 190 working. (I know, its the middle of winter) I have read prior posts about compressor oil. The pulley on my compressor is wet. Nothing is leaking nearby, and it is not leaving any sort of puddle. I am assuming that it is the oil in the compressor?? Is there a seal on the front of the compressor that can be replaced without evacuating the system? Is it hard to replace? I need a new push button unit, but when I jump the KLIMA relay the compressor engages and blows cold air, so everything else appears to be in working order. Would you recommend using the system in its present condition or replacing this seal? Is the oil available separately and how much does it hold? BTW it has the Nippon. compressor. Any opinions as to the overall reliability of the AC systems in the 190`s?

I know it is a lot of questions, but I really appreciate any thoughts.

Thank you and a Happy New Year. Tinker