The 72's all had the rubber strip. The 72 rear bumpers had rubber strips around the taillights. UticaGeoff
Believe that was the only difference between the '71 and '72s. Bumper were the same except '72s had the holes in them to accommodate the rubber impact (protective) strips.
I now have some info that the strips were an option for 72. # RPO VE5 ( N6 on the wholesale order form).
'71 & '72 rear look similar, excluding the impact strips. But look close at the carriage bolt location by the license plate. They are in different places. Not too big of a deal, unless your trying to mount the horse shoe bumperett around the license plate.