Riva Esterina, an Italian arms maker, used the DART mark for a line of guns that was imported by EXCAM. PR is the mark used by Riva Esterina's arms company, Officina Meccanica Armi Riva Esterina & Co for his black powder replicas line. Sometimes we see both the PR and the DART stamp on the same gun. The PR marking is to be found on replicas made from 1971 or 1972 up to 1979 or 1980. The PR line was imported into the USA and sold there by EIE, FIE, EIG and other importers such as EXCAM.