minor Major 7 combo

[CascoSieg]

A couple of years ago I started reading through a thread on this forum that focused on the Marshall Major, and whether and how one might capture the vibe of the original 200W item in a smaller scale. https://el34world.com/Forum/index.php?topic=17548.0
After working out and abandoning an ideal design/layout (due to funding constraints and the fact that I didn't think I actually "needed" another amp) I decided to use a donor amp that I was unable to sell, and build a combo version of the minor Major (my seventh build, as luck would have it!), salvaging whatever I could, namely the chassis, cab, speaker, switches, various and sundry components. Here's a link to a few pics if interested:
https://photos.app.goo.gl/d4tNKLT32JYsRQUS8
It turns out I DID need another amp after all! It's my new fave, especially with the Tele - turned out great, even in the odd format with all the constraints and compromises. I've never heard a Major in person, let alone played one, but this amp has a kick, an immediacy, massive bottom end and a clarity throughout the range, that I haven't experienced in any amp - Wow!
There's one odd thing, which may or may not be an issue: The plate voltages for all the small tubes came out pretty close to those listed in the Marshall Voltages spec that was floating around, except for the 12AU7 driver: mine are way short - 210v (leaving 9.1v at the cathode) instead of the spec'd 310v (leaving 15v). My B+ at that node (349v) must be way less than the Major, or something else I don't understand is going on. Given that (1) I'm only swinging current into two (instead of four) KT88's, and (2) 349v exceeds the typical max plate rating for the 12AU7, I'm wondering whether this is something that even in principle needs solving. In other words, does anyone with intimate knowledge of the Major think tweaking anything about the drivers (that would be possible in this amp) will make this amp behave more like the original?  FWIW the KT's are pushed plenty hard enough into overdrive for my liking, but as I've said, I've never heard a Major in person.
Thanks all, for the inspiration and guidance!

[GroundhogKen]

I think your driver voltages look reasonable based on the 12au7 datasheet.   And you did say it sounds good.
The B+ voltage on a real Major is close to 600.   The 12au7 plates on this schematic (see page 2) are 250v.   https://el34world.com/charts/Schematics/files/Marshall/Marshall_major_1966_200w_pa.pdf
I say if it ain't broke, don't fix it.
Nice job.

Ken