Given that these are the early style forks with the screw off chrome cap, I figured I'd just get a nice pin wrench to make life easier. With the fork in the vice, the pin wrench did its thing and they came apart quite easily.
These early style forks seem much simpler and with fewer parts than the other models shown in Clymer's. Though perhaps I just didn't get everything apart that could come apart. There was a circlip on the bottom of the tube that I took off, but then I couldn't figure out what it was holding on. It appeared to be the large cylinder with the grooves in it, but if so, that thing was on pretty tight. More research required...
Also seems pretty tough to clean out the inside of the tube thoroughly. Yahoo Groups didn't seem to have any brilliant tricks, either. Seems like just a long screwdriver, some kind of degreaser, and patience.
Oh, and also... the horn works!