Lined up with the edge of the bearing hole? Like they would press the bearing out if you stick a screw in them?BTW, This is an official part from ABB, not a shop made modification. The holes are lined up with the edge of the bearing hole, so i think the screws would hit the end bell housing. My guess is for some sort of arbor cover, but I have not seen anything listed in the catalog.
Do they not also have tool-grinding attachments that bold on the end?The guard acts as the bearing retainer on 3/4+ HP Baldors. These are for buffers, or a grinder with no guard. My other thought is possibly a belt sander attachment on the 3/4 hp.