A/C compressor makes noise

EVAP PRESSURE REGULATOR valve ... Ok . There should be a screen on those made of nylon to protect compressor at the suc inlet from any debris in system . Was that visible with any restrictions or perhaps torn / degraded so basically open ? Although you seemed to have short charged it correctly ( ballpark anyway) to compensate for R134a operation in a designed R12 system ... With that your pressures seem to be within spec range .
I mean I hate to condemn a compressor but they can operate properly( for awhile, depending on noise source) and make noise ... I've seen many many non mopar compressors do just that.
The EPR in my experience is not going to cause noise unless it's severely starving compressor of refrigerant and oil coming in from EVAP. But you would see that drastic condition with your gauges .
My money is on compressor ( reman , new , rebuilt I've seen them all defective as received but not overly much) but I'll be curious as to your findings when you further inspect.