Alas, my Farrow does not have an original buttplate (long story). Hopefully, Terry Buffum will tell us if that looks to be an original. My thought is that the casting is too thin, that there was a lot more metal in a Farrow. The checkering does not look at all like the original checkering on my Farrow. Also, no cheek piece. I thought Farrow put a cheek piece on all the single shots.
What are the markings & SN of the Ky. Krag? That should tell you more or less when the action was made. Is it a 30-40? Ouch!