Another MP24 mod in progress. (I'm building a mixer from scratch but realized I needed a little more education before proceeding with it....so this isn't gear buying, it's education!)
I found a "burning" MP24 locally for USD $40. 3 small resistors and capacitors later, I was in business. (Rane stuff is extremely well-engineered, so the burnt parts were just sacrificial resistors in front of op-amp power inputs.)
Bossa Nolyx graciously gave me his Front Panel design which I tweaked to personal taste. The only functional change I made was to add mechanical guides (little indentations on the rear of the panel) for the Alps RK27s. Cost was USD $210 for the front panel. I think the slightly higher cost was on account of using 4mm powder-coated metal as opposed to a slightly thinner anodized metal.
I should have this panel and the Sifam knob order by next week. Upon completion I'd be glad to give anyone my Front Panel file and the exact list of Sifam knobs I bought (which was fun to make, but a fairly involved task.) About USD $70 total for the knobs.