This is indeed a 20.5 as a picture of the output board indicates AP4. Picture upon request.
I decided for my piece of mind as well as the buyer's to have the unit cleaned and tested at the Levinson authorized repair facility, The Service Bench, in Norwood MA. The units 'tested to full output' to factory specifications. It did not need any replacement caps or any internals. While in there, I did have the speaker outputs changed from the Fischer connectors (just hard to find and I also heard from some enthusiasts that they did not want to change over their spade lugs to Fishers on their expensive speaker cable) to the Levinson speaker terminals. Also, during the previous owners stint with the unit, they replaced the Camac connectors for pre-amp input to RCA connectors. So, for those with 'modern' cables, this unit will fit right into your setup with ease.
Further, I believe these 20.5s were upgraded from 20s, as the backplate has number 20 (shown in the pictures) as does the inside bottom of the amp. Internal pictures of one amp upon request.
I have the original boxes. I am rating them 7 due to some very minor scratches on the backplate where the speakers/inputs are, which is quite normal. There is also a bump? on the rear handle as shown in the picture.
I am also listing for sale my McIntosh C-220 preamp which mated very well with these powerful and clean Class A amps. Due to the fact that I just paid close to $900 for the cleaning, testing, and new speaker terminals I have put the price at the 'last' price in the Audiogon listings. But, of course, I am open to reasonable offers.
New photos. Amps are now boxed and ready for shipping.