Charles,
Wow, thanks for those photos, they're great!
Now if I could just trouble you for a couple of other details.
Is there a small stamped number on the REAR bridge on the right side near the threaded holes and if so what is it?

Also, on that Whitty in the photos, are the foresight ramp and rearsight island attached by screws or are they soldered or brazed?

Are there any proofs stamped on the underside of the barrel?

Sorry for all these questions but I am doing a bit of research on these rifles and am trying to learn more about them.
I've seen quite a few different versions of the Whitworth Express and am trying to find out which were British assembley and which are not.
Thanks again Charles.