73 Valiant R12 AC system pressures

Compressor is not noisy, inside AC duct was blowing 70 when it was 85 outside.

What is the suction line temp returning to compressor? Could be a bit low on charge, something plugged, or evap cold and fan not high speed I like to at least get an estimate on supercooling which is given by low side pressure and low side temp. Are windows up? Some of those systems have that oddball suction pressure regulator but I don't think the little cars normally use it.