It is an end bell upright style OT that weighs better than twice what the old open frame OT does. I bought it from Angela.
Everything went well but it was quite a bit of work due to working around the circuit boards and feeding the wires through the existing grommets.
Once done I fired it up and re biased the amp because with some help from this forum, I figured out I had it pretty low at around 50% which was 35ma on this amp. It was suggested that I might get rid of a high fizzyness hash that has plagued this amp since I built it, by going hotter on the bias.
No such luck but it does sound better.
I biased it this time at 40ma which is still on the cold side at around 60%.
I didn't get to crank it real loud but what I heard I liked, I think the hotter bias more than anything helped this amp.
Seemed to have more of that reedy honk tone that I hear from other D amps.
I played it for about a half hour and reached around and felt the OT which was cool to the touch.
I hope to be able to turn it up to gigging volume tomorrow to hear and feel how it does.
I just centered it over the existing grommeted holes and drilled new mounting holes.
No added noise that I can detect which is a good thing.