Great minds think alike! Actually, a member of my club asked if I could do something with the front panel on the Harbor Freight box. The topic had also come up on the World Wide Slot Car Chat a few weeks ago. I was half way through my design when I got a message from Mac to ask if I'd give some feedback on his design. Since his was ready to print, I dropped it into slicer and sent it. His fit great, which gave me more confidence to continue my design. I finished it and printed it overnight. It popped right in and looks great, too. While I expect it to evolve over time, you kind of have to print and use a thing to figure out how to improve it.
While my model is 100% CAD by me, Mac beat me to the punch on the basic premise, so deserves all the love for his model, so I'm listing this as a remix of his. If your printer isn't big enough for my version or whatever, print his out. Don't forget to post a make! :)
Oh, and I printed this in the provided orientation. No need for supports because the actual bridging is super short when printed like that. Careful removing it from your print bed that you don't bend the print too much!
If you don't have a Harbor Freight tool box, but like the idea of the work surface with parts pockets and guide slot, I've uploaded a solid version for you. :)
The author remixed this model.
added pockets all around