Something is funky with that chainring. If you look at the close-up picture of the BSA mark, it¹s from another set of rings. Look at the position of the mark relative to the whole, as well as the tab that sticks out. There i s no way that mark is from that set of rings. I¹m with Bob, looks like TA ring, and I doubt it¹s track. That extra set of bash guard holes was found on cyclocross, but not track. Should only be one set of holes for 5 pin.
Sean Flores
San Francisco, CA