The cocking on opening on these is a modification, which is why I asked. That rifle seems to have had a careful job done to it. Looks like just about "everything" was done to it.
These actions were so common at the time that they were essentially just considered "parts". The reason that unaltered rifles are collectible today is that so few remain. Thank your nice sporter for sacrificing itself elegantly to increase the value of others... ;-)
A NICE sporter is still a work of art. That's a nice one.