I received an Gillette English Tech I bought on eBay that had an unusual case. The same case is shown with Gillette #24 English Tech (but not the Gillette English Tech I just got off eBay) in a 1958 ad shown on a B&B thread on Gillette English Techs. I do have a Gillette English Tech that looks like the #24 shown in the ad. That could mean the English Tech I just received was made in 1958 or a year or so after.