I've seen two different sets of stampings on Temperite blades, and I'm wondering if anyone has any information.

I've had two that were stamped "Temperite Trade Mark" on the front of the tang and "Made In the USA By Case" on the back.

I just recently got one that is stamped "Temperite Hand Forged" on the front of the tang and English Steel" on the back.

Are the different stampings indicative of production dates? I thought Case always used American steel? Was Temperite different from Case at some point?

Any information would be appreciated.