Jim, if you allow the air compressor to fill then sit it will accumulate moisture. Then spit on your neg and eventually rust the inside of the tank then spit rusty moisture onto your negs. These compressors work really well but you need to open the valve (at the bottom of the tank) after every use to blow out the moisture, then leave it open till your next use. I use mine all the time for dust control in the dark room. I also recommend using a second flow valve on the handle to further control the volume of air coming out in bursts. Don't want to accidently blow the neg out of the neg holder and scratch it.
Enjoy your new residence it looks great, Needs a little messing up though.