After a year or so on this project, I think it has finally wound down...
As last mentioned, I was working on getting the bias dialed in, and with that complete, and idle temperature remaining comfortable, the front plate and top cover went back on. Still a bit of an ugly duckling, but no longer a basket case, I brought it downstairs (literally one step at a time) and into the main system it went.
Happy to report that it sounds great and so far appears to be performing effortlessly. And one of the pleasant results to come out of this is that there is no "thump" at power up. Just the sound of the soft start relay clicking in and a very faint "tick" through the speakers that I assume is the reed relay on the buffer board as the protection circuit goes green.
I want to thank all who posted encouragement and assistance during the course of this project, and use this opportunity to encourage others to tackle projects that might seem daunting. With all of the valuable input from this forum, there is so much that can be learned. While there are aspects of this rebuild that I still have to scratch my head about, the frustrations were more than counterbalanced by the enlightenment provided.
So, let's see, what can I work on next...