Awesome piece of writing. Very cool... It was nice to see you used one of my old Mark IIA's as a reference photo. I sold that one to a cat in Australia last year. As a side note...you have a simple typo in the Mark I control description... Input 1 is the cascading high-gain channel whereas Input 2 would be known as the lower gain Fender-ish, Bassman-ish channel. Very concise and enjoyable read!
I take a small issue with the characterization "Bassman-ish". Assuming that we're talking about the classic and hallowed late '50s Fender bassman (the 1959 bassman is considered to be a holy grail), I think that there is very little that is Bassman-ish about the Fender-derived Boogies. From a circuit design perspective, I think that it is clear that all of the Mark series Boogies are derived from the classic 60s blackface Fender amps, not the late-50's bassman.
For example, in blackface Fender amps and in the Mark-series boogies, the preamp structure goes: gain -> tone knobs -> gain. But, on the late-50's bassman (and on Marshall amps), the pre-amp goes: gain-> cathode follower -> tone knobs. Also, the circuit values, the cutoff frequencies, and the insertion loss for the tone knobs are exactly the same between the Boogie and the blackface fender. They're quite different from the late-50's bassman.
These electrical design features of the pre-amp circuit have an important effect on the sound and feel of the amp as it is pushed into (by today's standards) mild overdrive. Some feel that these differences in the pre-amp between a classic Fender and a classic Marshall (which is derived from the late-50's bassman) are as important as Marshall's choice to switch from 6L6 to EL34 power tubes. So, we're not talking trivial differences here.
The only thing in the Boogie that is like the late 50's bassman is the inclusion of a "presence" knob. None (?) of the classic blackface Fender amps have this feature, though many of the Fender amps from the 50s did have it, including the late 50s bassman. But, the presence knob certainly wasn't unique to the bassman, and Fender started to re-introduce the presence knob on later amps (silverface?). So, I don't think that the presence knob is what the article was referring to as being "bassman-like".
So, to get back to my original point...I think that it's misleading to suggest that the early Boogies had anything to do with the late 50's bassmans.
But, if the reference was meant to point to the 60's bassmans, well, that's a whole different story. But did guitarists care about the 60's bassmans the way they did about the late 50's bassmans?