1983 Cadillac Deville A/C charging: how much coolant and p

Greetings. I have my father's 1983 Coupe deVille and am in the process of getting it road ready after having sat for many years. It has an actual and documented 16,005 miles. (That's not a typo. It's 16 thousand miles)

I'm ready to work on the A/C system and need to know how much coolant is required, and what the high side and low side pressures are supposed to be.

I realize that it's an R12 system for which freon is no longer available. However, I believe I have enough to at least charge and see if the system is functional

Thanks for the help.

Rick