MIMF

After 2 years of work on my first build, I was installing the string ferrals with my drill press when I heard a heart breaking crack! I'd stupidly installed the tone knobs first and the downward pressure on the back of the guitar forced the tone knob to break through the top of the guitar!
I was so close to finishing....
If someone could help me make this disappear I would be very grateful.

Ouch! I feel your pain.

For starters, take out the knobs, pots, and everything from the control cavity. Then try to press the wood out slowly from the inside and see if you can get it to reposition correctly flush with the top. If so, wick some CA glue into the crack all around.

Then you have to refinish that part of the top, but that's another story.

how smooth is the inside of your control cavity? Can you beef it up with a bit of veneer on the inside glued in cross grain?

Black limba isn't the strongest wood but that top looks exceptionally thin to me too. I'd shoot for a 1/4" top via the interior reinforcement. Most pots come in both a panel mount and a 3/8" tall threaded section for the wood topped control cavities.

CA glue repairs tend to be a little darker than what one would wish for so if there's any way you can accomplish what Peter suggests but using hot hide glue instead I'd try that first.

Yeah, first build, there's definitely some design faults, like overall thickness! I thought I was going to get away with it! Apparently not...
Thanks for the advise. Fingers crossed.