Monoprice Stage Right 15 Watt Tube Amp - with Mods & Upgrades

Modded Monoprice 15w tube amp. I've installed a 3-way bias selector switch on the rear. Down position is the stock Laney Cub configuration. Middle position is Marshall JCM preamp - reduced high end fizz vs stock. Up position is Fender-ish overdrive like a Blues Jr. The Fender position also gives this substantially more clean headroom if desired. All the PCB solder connections have been reflowed. Besides the stock speaker, solder quality is the only downside of these amps, reflowing it tends to reduce noise quite a bit. I also shielded the cabinet for reduced noise. Has the upgraded reverb tank. 
I've replaced the flat Celestion seventy80 speaker with an new Eminence that has better Mids for better crunch without flubbiness or fizz. The speaker isn't broken in yet, so it will need a few hours of playtime to develop full bass response. 
Stock tubes. I tried some JJs and just didn't hear any improvement. 
The factory tolex is sloppy on the rear...see pics. Looks good from the front.
Ships in the original double-box.