I've long had a project HW35 that I should finally get on with, the gun which is working, has a super rusty barrel & cylinder so badly pitted that if it would restore would surely cost far too much so I want to put all the working parts into a new cylinder with new barrel, servicing as I go of course.
It will be a Triggers broom but I was always intent on doing this.

I already had a cylinder (a KLS limited edition mentioned in another post recently) so I will need a barrel (Chambers £87 +vat but post to RFD of course).
Before I even start I see a difference at the safety button area, the old cylinder has a difference to the replacement one.
The difference is that there is another hole on the right of the cylinder and it's not like that on the old one, see picture where marked O & X.
This is where the button protrudes to the right side of the gun (as on my Export model) a change to that of early versions obviously, so my wreck must be much older, I wonder how old? serial 708755.
My main question therefore is will my safety button swap over (I haven't dismantled it yet) or will I need different parts and also what other issues may arise?

Visually and dimensionally I see no other problems.

I've never worked on a HW either so any pointers?


https://imgur.com/gallery/cqIY77U

TIA Steve