ryang:
Welcome to our forum. Seeing your snapshot of the old Gravely L model tractors was enough to convince me you are a good fit for our forum. I've used a 1965 L model Gravely for over 35 years, and also have a 10 HP Commercial model, still on the old L model transaxle. It seems like plenty of us who appreciate, collect, and use old machine tools often have a Gravely (or two or three) in our midst, and some of us also have an old motorcycle (or two or three) as well.
On the matter of your shaper: Simplex may well have been the dealer who sold it. If Simplex's name is on a metal tag fixed on the shaper with "excutcheon pins" (look like rivets and drive into blind holes to hold things like name or data plates), I'd say they were the dealer. Unfortunately, the name of the actual manufacturer of your shaper may have been cast on the access door or cover (which would close the opening to the internals in the main frame).
If your shaper is complete and nothing is excessively worn, broken, or otherwise non-functional, clean it up and put it to work. Old machine tools are made be firms that often are so long gone that no living being remembers where their plants were, nor are manuals are parts available. In short, we are on our own with them. I've made plenty of parts for my old Gravelys and motorcycles over the years, and plenty of tooling and whatnot on my old machine tools. It's part of the joys of old iron disease.
