awesome sir..it is a great razor..i love mine and my others..thank you for the kind words but expert i am not..i am learning this great hobby daily..british razors are my present obsession..for many reasons..
Reason I ask is that I purchased a #66 made in England razor set with one blade in the dispenser that has a code of K-1. 1965 I think looking at the Mr. Razor site for blades. Made me wonder how long the #66 sets were produced? The razor looks unused but I don't think that is the case? Maybe the blade dispenser was a later one after the original was used up. Maybe several years later? THE #66 set razor is definitely my favorite TTO Gillette razor!
the 4th generation #22/66 razor was slightly modded and plated in nickel and became the # 70, was available until the early 60s' ,,so 53 ish to 1960+.