According to the parts fiches, P/N 35013-MAJ-A32 is unique to ST1100 1995-2002 and ST1100 ABS 1996-2002.
Might want to call a place like Digi key.com. They have thousands of micro switches. One of the things I like about them is you can get a real person that will help you get the right switch. Check em out.
Sourcing the switch through either Digi-Key or OEM whether NOS or used are great ideas.
But keep in mind if the only part that's failing is the 'switch' then almost any Honda model from that design era which shares the same switchpod's outward appearance likely has the same switch inside. It's the length of the wires and the specific connectors at the other end that make the difference between one for the ST1100 or some other Honda model.
Were I in
@Scott Benesh 's shoes, I see at least three paths toward resolving the starter switch problem (with all due deference to
@Larry Fine and his point-on admonition to be sure the problem is the switch and not something else).
1. Get the exact or equivalent microswitch from Digi-Key and perform some soldering to swap out with the old.
Find a used 1991 through 2002 Honda whose right switchpod has the same shell and outward appearance and canabalize it for its switch.
Here I could go two ways...
2. Remove the switch and some length of its wires from the donor, cut the old switch out and splice the new one in its place. I know, blasphemy from STRider, but backed into a corner...
3. Do this if possible. Find a donor pod as above, detach the terminals for the starter switch from its connector. Do the same on the failing one. Fish them out of plastic sleeve or electrical tape wrap of the harness, swap and reverse the process. Guarantee the terminals fit the connector just like the originals did. The new wires might be too short, but if you sourced from, say a Shadow or cruiser with taller bars, the wires may in fact be too long, but I don't think it would be too hard to cable manage a few inches of excess wire underneath all that tupperware.