Actually, now that I think about it, the bolt is pictured in my Haynes manual, along with the snap ring. The text is a bit confusing since they seem to mix disassembly of the auto vs. manual hubs in the same paragraphs, but the photos do indeed show a bolt on the end of the shaft. Page 8-14, figure 18.6a. There's no mention of the bolt in the text, maybe they were just using it to pull out the shaft...perhaps the previous owner saw this. The photos that show removal of the cap on the autos don't show a bolt.

2000 Mitsubishi Montero Endeavor, "Katsumi", 138k
1993 Toyota Tercel, backup vehicle, 93k
1989 Isuzu Trooper, "Beniko", R.I.P. at 233k

My 'Genuine Isuzu Parts' decals - for sale