What I have here is a 68/4500 Air America 68/4500 Carleton Tank. Hydro'd in 04/08, so its good for awhile. The tank has always been covered and is in great condition. You can either use this as an adjustable Regulator and manually raise the pressure from 75psi. up to 1200 psi.
Price: $150 obo
Pic from previous owner (i only have a webcam):