Just thought I would follow up on this. After some digging around, I determined that the Bosch F-OOM-145-230 voltage regulator would work with my Bosch 0124515019 120 Amp alternator. In fact, that was what was the part number on the voltage regulator in my alternator when I pulled it. At ~$40 in aftermarket (Transpo IB230), this is far cheaper than the one that FCPgroton.com has listed at $136. The original VR had very worn brushes.

It was possible, but not fun, to remove the Phillips screw on the alternator back cover behind the intake manifold using a small ratchet. After that the job is easy. One minor setback-- I dropped this screw on reassembly and couldn't find it (probably will when the ice finally melts!).

The spec on the set point for this regulator is 14.1V. I'm seeing 13.9V at the battery terminals, which is good. I still need to order a proper positive cable-- I tried the flux and solder on the original cable, but it wasn't successful, so I have a temporary cable in place now.