I have finished "restoring" my AC system, even bought more freon, but have yet to get to my buddie's shop and suck off the car.
AC system mods
New expansion valve, all O-Rings, Valve cores and caps, and drier.
Polished every hard line and the drier. (polished by hand with steel wool and then Mothers)
Ran Rubbing Achohol through everything, then a "professional" purge chemical.
If nothing else it looks good... the rest of the engine is dirtier than all heck - but hey it's progress. I've got to sand and paint (rust) a few more brackets up under the dash, then I can install/reconnect the radio and get some other wiring done.
Near future plans... some more dynamat extreme on the rear pillars and roof section, seem sealer on the roof supports, get the remaining tint off and repair the broken defroster lines... then I can retint the back and side windows, put in some fiberglass speaker boxes.... etc.... etc....