Hey Mj,
Ok.. this morning I had chance to take a look inside and get some snaps of what my amp tech has done. You can see that the pot itself is a variable resistor and I have given you close ups of where you need to wire it up. It is shielded wire, and I assume it will be a linear pot. If you can handle getting beneath the PCB (I'm a little ham fisted when it comes to things like this, I can wire up a guitar.. but this is a little too intricate for me!), then have a go.. these photos should give you a good idea of how to go about it.
Your recording sounds good, the only thing I would do differently is the EQ, I spent a few months playing this amp with the bass maxed as you are.. but now I have it around 2 o'clock for both strat style and humbucker guitars. I'd have the treble around 10 o'clock (strat) or 2 o'clock (humbucks) and mids between 12 and 2 o'clock for both strat and humbucks.. this is on class A or A/B and with the interactive EQ. Oh, and for the drive channel I have the second mid control around 2 o'clock, that seems to balance the two channels out. At higher volumes you will find you need to back off the bass from here and maybe push up the mids a little.. it gets too woofy in a band situation.
With the MV mod, you can get some nice tube saturation at bedroom volume and even some harmonic overlays. I'm about to test it out for real tonight though, we have band rehearsal tonight.. I shall report back with my results of what it sounds like cranked.
With a little tweaking this amp is really, really nice. It takes pedals really well, I use a Big Muff Tone Wicker most of the time.. with a cranked amp, that thing sounds sweet. I have just ordered a HBE Germania from PGS as well.
Hope this is helpful.
Danny