This is really neat stuff man. As a fabricator myself, I love your attention to the fine details that most people would easily overlook. I'm going to use that aluminum graining tip on my next build!
Awesome to meet another fabricator! Glad to hear some of the info was new and useful. The devil is in the details as they say! Good luck on future builds!
The holes are drilled specifically for the strong hand hold down clamps you can see in them. The layout and the surface of the 1" thick table top are by no means square of level due to wear over time. Hope this gave some insight!
