Vintage Craftool Swivel Knife

I bought this swivel knife on eBay recently. The knife is an earlier Craftool and only the saddle and stem are chrome plated. The barrel has really nice and crisp checkering, but is non-plated steel. I haven't seen any others like this, but I am guessing that this non-adjustable model was fairly common. Judging by my other Craftool swivel knives that I know the approximate dates on, I think this tool may be from the early to mid-1950's. Any comments/corrections here are appreciated.