So long story short, I picked up a pursuit bike off CL recently and the seller threw in this disc wheel and I'm having a hard time identifying it as it intrigues me. Older tubular disc, alloy brake track with what appears to be plywood (?) outer with corrugated cardboard in between or similar material connecting to an alloy flange around the hub. Hub is threaded for a freewheel, but has a spacer that allows a track cog to be run. Since I'm newer to disc wheels I'm curious as to what the history/story about the wheel is but my searches are coming up dry, anyone have some insight?