vintage PS Audio Moving Coil Amplifer

i have an older PS Audio Moving Coil Amplifier that i got off eBay in an auction i won along with some other vintage PS Audio gear. this piece, which is in [apparently] decent shape, has been sitting unused in a closet.

since there is no data available in the A-gon Blue Book on this piece, i thought i'd see if anyone knows anything about them. please share opinions, thoughts, info, etc.?

thank you.
well this thread had over 200 views at one point, but no responses. the piece in question is at auction right now, ending Monday Dec. 20. 1.00 no reserve, if anyone is interested.