This thread seems to have expanded to cover both (1) which vintage Mac amp and (2) how to ship it.
I have purchased about 20 Mac units - all via bidding sites. My experience has mostly been successful, although I have refused delivery on some units because of damage in transit. When they were new the factory Mac shipping boxes were great. But, time and humidity (especially living on the Gulf Coast) make older boxes unreliable. Remember, cardboard is just glorified paper. Paper does not survive well with humidity.
I have found the shipping boxes for Audio Classics to be the preferred method. The last boxes I got from them had a pretty heavy fiberboard base for mounting the equipment. I believe someone earlier in this thread mentioned plywood. 3/4 plywood make an outstanding base for mounting.
I did have one unit with a broken face plate. I found a replacement on a bidding website. This was an MC2255 that was used in development of Apogee speakers, when they were very highly rated by Stereophile. It was worth the extra cost to me to have a machine with that pdeigree.
As to power amps, I like the MC2255. This was the last amp with a chrome chassis. And, it had other features not on later amps. I have 2205s, 2255s, and 7270s. At my age I cannot hear a difference. I am using 2255s to drive re-built KLH Model Nines full range electrostatics. To me, in my small apartment, it is audio nirvana.
Thanks,
Jim