I'm one of the AT layout's biggest fans so it's great to see more AT customs. It's also nice to see a AT custom with some actual bezel on it like the IBM gods intended, shame there's no pen holder though.
Personally I'm not the biggest fan of how the fixed cable is implemented. While it coming out on the right side is directly inspired from the G80-0413 it's a major inconvenience in this day and age. I also don't know if a fixed cable is the best idea for a board that weighs 5kg, I don't want to imagine what would happen in a scenario where the board was only held up by the cable.
I also think the top mount mounting points really need to be reworked, mainly the side mounting points. The way it's currently setup would most likely feel very inconsistent, I imagine it would be so bad that I would only consider building this plateless gasket mount.
Despite those two grievances I have I'm still really looking forward to this and hope those issues can be ironed out before the GB is launched. It's always great to see more vint inspired customs and a 5KG board at this price is pretty hard to beat.
One other point of feedback real quick:
A complete picture of the back would be nice.
Edit:
After filling out the IC I saw the part about whether or not to move the knob to the top case. I figured I would put my feedback here as well since I would be very disappointed if it was moved up there.
Personally I would not move the knob to the top of the keyboard. It being on the right side where most people use their mouse is actually pretty useful, you can just move your mouse near the knob and use your thumb to turn it.
I also think a knob on the top would ruin the vintage feel of the board. There are not many vintage keyboards with a knob, let alone one on the top. Knobs on the side aren't completely unheard of for vints and overall I think if there is a knob keeping it on the side fits the theme much better.