My Vintage air has a A/C temp switch, it adjusts the compressor cut in and out pressures, so if it freezes up, I adjusts it up just a smidge. Its not as cold but it keeps from freezing up in high humidity. Also mine runs really low side pressure, like 5 - 10 psi when its on max cool and the cab is cold. I don't remember what the high side was. They don't hold much freon, something like 1. 4 lbs, but don't hold me to that number.
