I have an 82901 too! I have two accessories that could be what you're looking for. The least likely is the 82955 Trim Guide, a circular disc with a centered adjustable bearing race. The assembly mounts to the 82901 base for freehand edge work. The other item that really seems to be what you need has no model # nor badging, which is odd, because it's MADE for the 82901--two rails that anchor into the 82901 base, and an adjustable guide assembly that runs along the rails which fine-adjusts the guide's distance from the bit. I don't see any evidence of a stamping or other I.D. And now I'm curious if what I have was made by Stanley. I got it all together at the same time. If that disc is what you need, then at least that has a model number. Good luck.