I'm sure I could search for the specs-but what is the correct charge amount?
Also-R-12 is very expensive-has anyone tried charging with R-134a?
The typical charge is about 9oz R12, but if your evap' tubbing has detached from the tank wall there will be a poor heat exchange and flood the evaporator with freon & this will cause the suction line to ice up too. ( sliders refrigeration systems can be so much fun to work on)
The old compressor wont much like it at all (R134a) & the cap' tube is the wrong spec's for it too. and if you try to add POE oil to the system ( to help make the Mineral Oil (abbreviated as "MO" oil) more compatible it will quickly react to any moisture trapped in the MO oil & plug the capillary tube or afore mentioned filter sieve.
Freeze12 is a nice (so called) drop in replacement for R12. and you don't need a license to buy it off of Ebay.