@ Darren, I too "collect" bearing races. Long ago I found they helped when installing a new replacement bearing in a recessed bore or a bearing over shaft, I cut the race with angle grinder, torch, etc. This allows the race to contract or expand slightly allowing easy removal from shaft or bore after pushing new bearing into place. Chamfer the edges of the cut you made before using. Using an old race allows pushing farther away from bearing seals and races, less trying to find the "perfect" piece to machine/make something to install a bearing.