Except for the different sights, which look better, isn't that just a Webley Typhoon?
Big and heavy, but not in a good way, with a poor grip.
My Typhoon, bought brand new, had minor rust spots on the piston when I stripped it down for a re-lube as soon as I got it - I rather thought that was necessary from a strip-down article in one of the magazines.
After that it wasn't terrible to shoot, I did use it a little, but it was never a really pleasant gun to use.
Regards,
Iain