Isn't this an A&W (Anson & Webley) rather than A&WC (Anson & Webley cordite) model?
The bar is shorter on the non-cordite version, which seems to be the case for this gun.
I really like the Webley Screw Grip... It's a wonderful design.
I don't think that I have ever seen a Wm Evans gun that was not a screw grip.
Manton (& Co of course) has used A&W actionned guns even for their 470NEs.

Best regards,
WC-