1971 A/C What do I have?

[Hack71]

I need some help or advise.
My Truck sometime before me was converted to you 134a, the only reason I know is by the different fittings. When I bought the truck the A/C blew warm air. It had pressure not sure how much though. I evacuated the system (my own pump and it held at -30, +1 or - 1. turned the pump off and watched for 3-4 hours it held with no leaks, I installed new oil and about 3.5 lbs 134a approximately. The a/c was notably cooler, so I thought it just needed the recharge. The first couple of warm days, not hot maybe 85 and sunny it would not keep the truck cool the vents were still blowing cool air but not cold, I never put a thermometer in the vent for the actual temp. Last winter I tore down the truck to do various repairs as noted in my build thread, the a/c was disconnected and removed (still was charged). My thought is either go back to R-12 or continue down the path of 134a, I have heard talk of replacing the condenser with a larger one and the expansion valve being replaced with a POA valve and or adjusting the pressure on the POA to a lower setting.
I'm not sure what I have so I have attached a picture. Any help or input would be great!! also heard that I will need to replace the o rings and rubber lines because of the different oil. Trying to save a buck! If money wasn't an object I would just replace it all! I believe what I have is useable stuff.