Updating a 64 Dart vert

Around here the broke cops have been handing out seat belt tickets if you do not have a shoulder belt showing even if your car did not have them.
I would definitely fight that in court, plus sue them for harrassment. Seems like an easy win since you must be grand-fathered in, at least every state I have lived is such. To do otherwise would violate the "no ex post facto laws" in the U.S. Constitution.

That said, I feel naked driving without a shoulder belt. I do so in my 65 Newport, but it is 4000 lbs and I don't drive it outside of work much. I plan a shoulder belt for my 65 Dart.