A tiny bit of progress.

I finally tore into the front wheel, to inspect the brake and see if it needed anything. Other than a good clean, no. All in good shape.

The large nut you can see on the air scoop is the one that locks the brake plate against the hub. You need a 28mm pipe wrench to undo it, whilst locking the spindle on the other side in a vice or with a pair of locking pliers. Care must be taken not to damage the spindle when doing this. Lunmad explains it much better in his front wheel videos.

Inside you can see it's all so dirty it's practically fuzzy, but this is actually a good sign as it means that nobody has been in here for a very long time. An unmolested front brake (possibly the entire front end) albeit dirty, is a real bonus.

The inside of the hub hasn't fared so well unfortunately. It's not the oxidation that concerns me, that's only superficial and easily removed (it's probably due to a bit of condensation and lack of use over the last few years, again, not a bad thing). The braking surface, however, shows some pretty deep grooves... with matching ridges on the brake shoes. I'll leave it alone for now, but this might require some attention later on.
The bearings are definitely the original ones, you can tell they have never been replaced because nobody has messed with the lockring, buggering it with a sledge hammer before realising it's a LEFT hand thread.
They're in good shape and I could use the wheel as it is, but it might be a good idea to replace the bearings now that the wheel is under maintenance. The chrome isn't very good, on both rims but I don't mind. The finished motorcycle will not be a clean, sterile machine, it's going to look about 35/40 years old from the moment it's ready.

After a good clean it's all starting to look much better. All the bits are there and in good shape, there is no need to replace anything (we'll see about the shoes). The inside of the brake plate is stamped '71' and it carries the original (riveted) Lockheed shoes. Nice.

I know it's not surgically clean, but the point was to inspect the parts for damage. Since we're still a LONG way away from actually using this component for its intended purpose, I'm satisfied for now.