zaphod wrote:
To make it even cooler dismantle the Normal preamp, and parallel up the now spare triode with the TMB channel's first triode. Now put in an EF86 in for your Normal channel, following the TC-15's EF86 channel design. You will then have an amp with one Vox channel and one Marshall channel.

You've just described the perfect 18 watt amp to me. While I lurked and debated between the sIII and Plexi, you've described one better than both ... IMO.
My favorite personal amp all time was a Trace Elliot Velocette. Great, Vox type tones, but I hated the lower rear controls. I've steered away from the TC-15 because, as much as I liked my Velocette, I never really thought much of Matchless Lightnings. Yeah, I must be weird. But to have a Vox type channel and a Marshall type channel would be outrageous.