I am an HVAC tech I have never worked on coolers. A friend of mine got a small reach-in cooler and it seems that the compressor may be bad. There is no nameplate on the cooler anywhere. All I could find was a plate on the compressor and it reads as follows:

AJ311 BJ-424
G B22 82C 95300 AJ6435A
V115 Hz 60 LRA 38.2
v110 Hz 50 PH1

It is a small unit I don't think the LRA is 38.2 but that is what it looked like. Anyway what brand, Hp, refrigerant type would this be most likely R-12 I figure but what about the rest?