Hello Roger,
That is the Stanley 45 combination plane and is used to cut molding, McRabbets and dadoes. Stanley introduced the plane in the 1880's and continued to make it until the 1950's. Depending on the year/model, the plane came with 21-24 cutters, extra short rods, several different depth stops, a screwdriver, and the older ones came in a nifty finger joint wooden box. A variety of special cutters and plane bottoms were also available from Stanley. Nice examples of the 45 are very collectible particularly when they have the cutters, misc. gadgets and especially the box. They also a very useful plane in the shop if you know how to use them. For some operations they are faster to set up and use than a router or shaper, plus you have a lot more control over the cut. That particular plane in the ebay auction was made around 1900 and is in pretty sad shape. The rosewood is gone off the fence, a lot of the plating is missing, a lot of rust, plus none of the cutters or misc parts are present. That plane is probably worth $20 - $30. It would be very difficult (impossible?)to restore to collectible status, but could be resurrected to make a pretty good user. $125 that the seller is asking is totally out of consideration.
My Best
Randy
