Having owned the 2125, 2155,2205, 2255, 2002, and my all-time favorite-the MC7200, you will find a big difference between the model you tried and the 7200. Personally, I have never been enamored of Mac's amps with the autoformers, the bass sounding flabby and not crisp and tight. My 7200 is direct-coupled, with great bass. I have not tried the new amps, as cost is prohibitive in retirement!
The problems you described with lighting could just be that-sounds like bulbs need to be replaced. Some Mac amps of that vintage had a circuit board for each meter, and sometimes they needed to be pulled out of their mounting slots and contacts cleaned, and re-inserted. I had a lot of trouble with one 2155's meters doing what you describe, as I recall. The power cord can be changed, but Mac felt it was fine at the time, so that would'nt be an issue with me. Rust is another issue, however, depending on what/where it is.
Everyone seems to rave about the new stuff, although I sure see a lot of them going up for sale here on the 'Gon. If you want more expert advice, contact "Aball" (Arthur) here on Audiogon-he's tried lots of Mac gear, and has some pretty sound advice.