You guys made me curious! Just looked at our 68 CS ( a pretty good, untampered with car in most respects) and it has them on both outer bumper brace tubes. They consist on this car on a length of rubber hose, very much like heater hose. Each one has a ribbed section and that is where the "split" is made. They are now a rather oblong shape but could have been round when they were new. The split follows the ribbed area and appears too precise to have been hacked up by someone. They are easy to remove and it is hard to imagine that they have remained in place for 42 years. Am unable to post images here but if anyone wants a picture I will remove them and email a photo to someone who will post it. Anyway, at least on this particular car the rubber hose is indeed on both sides and toward the forward edge of the tubular brace.