The Theoben sights are not the original - by a few years!
I don't think that is a shroud, I think it is all barrel - I think Webley used a cut down barrel from a German '88 to make the Osprey
I seem to remember the spring was supposed to flick the lever open to about 10 degrees - ie up against the cylinder prior to cocking, not sure about it's position after that
"But we have our own dream and our own task. We are with Europe, but not of it. We are linked, but not comprised. We are interested and associated, but not absorbed."
Winston Churchill 1930