Peter, it's (hopefully) unlikely that somebody would have broken off BOTH ends of both circlips but reused them anyway. But you never know.
What's more likely is that you have a type of circlip that only has 2 cutouts for a flat screwdriver blade, on the outside of each end of the circlip. Actually quite common for fork seals. Clean off as much rust and grime as you can and have a good look. The good news is if that's what you've got, you just stick in a screwdriver on one side (in the cutout) and twist; if it starts to come out of the groove, use another small flatbladed screwdriver to slip in under the partially released circlip and hold it out of the groove. Once one end of the circlip is out of the groove you should be able to gently pry the rest out very easily.
And if you do damage the circlip getting it out, you should be able to get a couple with little holes from your friendly bearing supplier to replace the originals.
Ken