N5X British Overdrive amplifier

As I’m gearing up to make this N5X British Overdrive amplifier DIY kit

as a buddy for the Marshall DSL5CR with upgraded Celestion G10 Vintage,

I was contemplating how to house it, build a cab for just the amp head, and/or then build another Thiele TL806 cabinet?
Meanwhile that Marshall has a 12AY7 V2 tube to tame the overkill madness of the Ultra Gain channel, a diy clone of the EWC SVC in the fx-loop and a Speaker Soak between amp out and speaker to be able to overdrive pre-amp and power-amp tubes while playing livingroom or even bedroom levels.

Scrolling the interwebs I found an empty housing for a Mesa Boogie MKIV combo, which looks very promising

so next, look for a speaker for it.

The MB MKIV can house a 12inch speaker and the choice quickly fell on the Celestion T4534 G12H 16 Ohm 30 Watts, 70th Anniversary edition and not only cause I found a B-stock version of it 😉

Which together (Marshall and N5X combos played together through clone diy of the Lehle P-Split) will look kinda like (sound as) this

However it turns out that the 12 inch speaker hole in the Mesa housing is 279.55mm wide and the G12H speaker needs 297mm hole so gonna buy a 22 degree angled outer bit so it may fit snugly, I hope