Cornelius Compact 50 Freon Charge

[fkg41]

I have asked several different refrigeration people and every one thus far has given me a different number. An outfit in North Carolina said 15 lbs on low side and on this site everyone has a different number. Surely there is someone out there that has had a Cornelius Compact 50 that had to have a freon charge. Has anyone got a manual or perhaps knows someone that worked for Cornelius and would know.
I don't want to start putting freon into the compressor without knowing what the reading should be because I don't want to blow the valves out of it.
I need to also mention that on #1 setting on the thermostat, the box functions perfectly with a constant temperature of 40 degrees on bottled drinks. Go to settings 2-3-4 or above and the coil frosts and eventually freexes up though the temperature of the box remains 40 degrees until the frost and ice block the air flow thus raisisng the temperature to 45 degree. I need 28-30 degrees for perfect beer temperature. I don't like it shadetree cool, I like it with ice crystals in it.

[globalcompressors]

If you're overcharged, the coil will freeze up. If you have a poor seal around the lid, the coil will freeze up.
Good seal, 40 degrees in the box, you should be running about 8-10 psi on your low side gauge. Any higher,
the coil is over saturated and frost will be returning down the line, to the compressor. As the temperature
in the box drops, so will the psi on the low gauge. 30 degree box temperature, 3-5 psi on the gauge.

[Yarochrehc]

That's correct, you should never have the low side pressure any higher than 10 inches of pressure, as said earilier it will flood the evap with R12. Most cap tube systems run around 5 inches.