Thanks for the feedback; I learned something too re the mounts. I can't entirely tell from the photos if the bolt is straight or not. It certainly does appear to be raked in one image as Kamilaroi notes, and the checkering is definitely not right. Wonder if the bolt handle was swapped out at some point? Even though I'm not looking to buy, I enjoy looking at these old rifles and am trying to learn more about them. I haven't seen many 1903s relative to some of the other model variations.
Kind regards,
Bill