Yeah, Bear sold those shafts but I don't know who made them. Ron is likely right about Fleetwood. I think they preceded the aluminum insert shafts. I had a couple dozen of these arrows. I've got a couple left, and ground a hole in the side of one to see what was done. They just used a wooden dowel as a plug and ground it off. I had some old glass shafts without the proper insert and found a dowel that was close and tried it. The thing about it is the dowel actually doesn't have to fit perfectly. I used a Woodchuck, but any grinder that locates off the shaft OD will grind the taper to be pretty well aligned. Was so impressed that I later tried it on an aluminum shaft just to see if it worked....it did.
Quite a find though, I think. Congratulations.