I have choke tubesin 12 and 20 ga. that say POWerPAC....Long range,med range, short range on them...quite a large choking system.....knurled ring with spanner hole...leather case...Can anyone tell me the era, maker, or another info on the chokes.....were the factory or aftermarket? thanks for the help...Hal

The POWer-PAC chokes were made by Pachmayer. They were factory installed on some guns, such as the Sears J.C. Higgins Model 20. I believe they were available aftermarket as well. Sorry I don't mave much information on the dates of manufacture, but the J.C. Higgins Model 20 was produced in the 1950s.
Uplander