CR is Chicago Rawhide,a compnay that makes seals.
If you do a search for McCulloch parts on the internet you will find several companys listed in upstate New York.One is in Fayettevile and one in Maryland New York in addition,one in Seamans Ohio . All I think are on here but I don't know if they are sponsers so being such a law abiding person regarding the sites policy,I can't publish a link to them.I would be willing to bet they would have those seals.If not,about any good bearing supply house should be able to cross reference them.They shouldn't be over 5 or 6 bucks a piece.