Thanks - and massive apologies for laziness as I've just seen the reach detailed in the OP.
Just measured the quill on the one it would replace and it is 0.8inch (22mm) which seems very strange, and clearly not 11/8 - so I'll have to pass.
Edited - wally alert, the one I've got is a 1 incher isn't it and I'm measuring wrong - doh.