Why isnt R12 AC refrigerant used anymore?

I went out and bought a cheap AC retrofit kit to change from R12 to R134 but I cant seem to figure out what is going on with my stock fittings. Took this picture last night of how that car was when I bought it.

What did the PO do? How do I retro the new kit in?
ANY help would be great!! It was 101 down here yesterday so I need AC ASAP