Does anyone know the year of these?

Hello,

I recently acquired a pair of Smith & Wesson Model 100 cuffs & I was wondering if anyone knew the approximate year they were made.
They are marked "Pats pending" on the sides, were made in Springfield Mass., and have the double lock slot on the keyhole side only. They are also a brighter nickel finish then the current satin nickel 100's. I am assuming they are the first run of Model 100's after S&W stopped making the Model 90's. Any help would be appreciated.

Thanks,
David