Cat 277 tracks

I have a cat 277 mtl with rubber tracks. I've purchased new tracks individually one at a time and once again am in the market for one due to one coming Apart. I'm trying to locate a good used track to match the good one still on the machine. I was wondering if any one has something out there or perhaps someone could point me In the right direction of a good used track. Might be a shot in the dark because I know how tracks with these machines are but no harm In asking. Thanks.