British contract Spanish OP No2 Mk1 revolver

Just picked this up. According to my research, this is a British contract Spanish .455 revolver (OP No2 Mk1)
Apparently this model was only produced by Trocaola. These, again apparently, generally never show British proofs, only Spanish.
I'm guessing made in 1915, do not know if this is one of the 6000 rejected by the British government.
This example appears very well made, tight all over, attractive case hardening on the hammer and trigger. Unfortunately the rear of the cylinder has been shaved.
Enjoy the two pics I have at the moment. Any additional info on these would be appreciated!

Shaved, as in using .45ACP and clips?

Yessir. However, I have a way to convert .45 ACP clips to accept .455, lol.
Now I've always done that for shaved Webleys, and it's worked great. A Spanish .455 might be interesting. And by interesting I mean what the hell am I thinking.

Why not just use .45 auto rim and be done?