I might have done it differently..
If I could get the switch to clean the panel I would just disassemble it with the wires attached. 
Good work...
I hate broken switches.
Good luck on that 221. I really hate those amps. Not sure why but never cared for the,. I do like the Drake L4B.
Sounds like you indeed have a busy year planned out. I really wish I had time to do all the stuff I wanted to. I turn down so much work. I know just this past week end I told seven folks no on sending in repairs. just no time and I do have a back log.
I agree with you on leaving the wires attached. But I try and keep the folks learning in mind. Since each wafer is tied to the other with jumpers you have to be really careful in taking it apart. When all the wires are removed I think it would be an easy repair, other than dealing with the wires. 
The SB-220 / 221 are built to a cost but well built for that cost.
This makes my second amplifier in that line. I have an SB-220 I picked up for a decent price. that required some work. The link is here.....
http://forums.qrz.com/index.php?threads/sb-220-find.372651/The person who built it ran it for a time then modified it for 160 meters. I didn't like the mod, it was not well executed, so I returned that section to stock and then proceeded to modify the amplifier myself.
The power supply was upgraded, larger diodes, the whole high voltage board was rebuilt with better parts. filter caps were doubled giving 50MF at 3600V. A better plate choke was used . Step start inrush current limiting was added. There is more to be done, and this follow on project has been pushed back three years now.

I wouldn't run this amplifier at full power on RTTY the transformer is only rated for 800VA
But the larger caps in the power supply made a big improvement in dynamic regulation.
Phase two will be to replace the T/R relay and bias circuit, Phase three is a new plate transformer that is rated for 1.5KVA. At that point it's not an SB-220 anymore.
The SB-221 will get similar treatment...