After doing some more thinking and looking, I've decided that what's probably the most logical thing to do is adapt brakes from something more readily available. After doing a little cursory looking, I found that the a Kawasaki Ninja 250R has similar weight, about the same rotor size (same rotor size for the 88-07 models, in 2008-12 they went to 30mm larger fronts and 10mm smaller rears - go figure). Oh, and a lot of people wreck the things apparently so parts are available cheap on eBay from everywhere, including lots of assemblies where the master cylinder, caliper, and hose are all there (I expect I'll need to have new hoses made for the correct length). The 250R also has the same 7/8" standard bar size (like virtually every other non-Harley out there), so that should bolt up easily there. Really what I'll need to fabricate will be caliper mounting brackets to get them fitting right, and that shouldn't be too difficult to do.
Like I said, brakes have never stopped me before.
I'm also looking at the electrical system on this thing. Like much of the rest of the bike, it's a unique design that I think was based largely on limitations of what existed in those days, and trying to minimize weight. The alternator is a 6V/12V setup. 12V goes to the ignition system, and the alternator is the sole source of power to the ignition. The rest of the bike gets 6V (battery is 6V). The systems are separate once they leave the alternator.
Some people complain about this setup, but looking at it it would be fairly easy to convert to a dedicated 12V system if I so chose, which might make starting easier as well (having not started this at all, I have no idea how easy or hard it is to start). But seeing how this is all put together, I think I could make that work fairly easily if needed and basically just change out bulbs since that the electrical system outside of the ignition is nothing but bulbs and indicator lights. Even the tach and speedo are mechanical.
The oil filter on it is really a screen that you clean out, but the gasket is something that may need to get replaced (although it is reusable). So I'll probably drain the oil, pull the filter, and see how that all looks. Do the valve lash, find a new air filter (just find something universal which should be easy enough to do), test the ignition system to make sure it seems to be working, see if I can get a burble on starter fluid, and then work on the carbs and put it all together. Oh, and clean/seal the tank.
The ignition boxes (as well as the alternator) say Ducati on them. But the ground wires for those boxes are both corroded and the insulation is falling off. They also are not replaceable, the boxes are sealed. So we'll see about those, if there are ignition issues, I'll bet that's where they come from.