and i'd bet it's gonna take more than 2-4 hours..

Yup, without a real bench and bench tools, I'd say my humble effort took at least that long. I may have spent 2 hours just filing the opening for the sled by hand after cutting it out with a jigsaw. I have a Dremel, too, but, for better or worse, those little bits don't remove a lot of material quickly. Aluminum is pretty reasonable ot work with, but it still takes time. I got an e-mail asking if I could build another, but I am not set up for it. If somebody was, I think it would be a reasonable proposition to make some in a batch of 10, say.

Side note, FWIW: With aluminum filings flying all over the place there's the potential to scratch the front of the anodized plate. One thing I did before using the jigsaw was to cover the entire front of the piece with two thicknesses of that wide, blue (low-residue) masking tapoe.