well, i'm going to attempt to get the A/C working in my square body '94 s10 blazer... i ordered a vacuum pump.. so i guess i'll try to pull a vac down on it.. and then i'll know if there is a catastrophic leak ... (there may be refrigerant in it... I haven't put the gauges on it yet)
also ordered a UV dye kit...

 

I did a full rebuild of my AC system on my 99 a few years ago. I'm not sure if the differences between mine and yours are very great, but you might check out what I did on my build thread in case you go down that road.

I think the worst part of the job was having to drain the cooling system to get at the condenser.

Good Luck and keep us posted.