Your pressures look good. The low side might be a little low if its still R12.
The pressures are probably not your problem. The fact that it takes recycling the key may not mean anything other than to say that is probably a controlller issue. I would say that that is the way the comressor controller works though. If it sees a engine problem, probably only voltage or rpm on your car, it shuts down untill the key is cycled.
Bosch Master, ASE Master, L1
33 years MB technician