I have seen both and would love to find a true Cal..22 barrel, Have one like that and rest are either "Parker Rifled" with the round stamp on end of barrel or just unmarked. I just found this receiver and thought it should be returned to life. I obtained a bunch of bolt heads, extractors and firing pin sets from Israel years ago, all packed in the old red Webley revolver boxes. At the time the boxes were worth good money to collectors. Also found a No 1 Mk V in same pile. I had a rifle I had cut in a police destruction maybe 12-15 years ago so have most parts for that receiver. Just trying to complete some projects. Sometimes it takes that long to get the parts all together. Still working on one No 1 Mk VI.