1970 seat belts are are 1 year specific. The 71-74 styles are basically the same. You can use buckle assemblies from other Mopar models as well when building a set. The problem is that few know which are correct for what and the proper length and design to sew the new belts to.
The real cost in belts is restoration costs, Snake Oyl charges allot (500-900 or so) to restore complete sets of belts. The guy on ebay has apparenlty found an original set of 70 E-body belts, copied the style/design replated the buckles, painted the latches, and replaced all the old belts with new, and added new new tags. Snake Oyl will not supply part#/date coded tags as they are a Chrysler copyright infringed part to manufacture, the current seller/restorer must know this and is ignoring it?
At any rate, with that in hand, I'm sure some buyers would rather not hunt the belts down, spend the money (and especially the time) to get some done themselves, it would likely save some money, yes, but many doing high end E-body cars find money to be less important than time.
