Webley Hawks work well with one piece mounts, which are readily available from the internet. For a quality mount, Sportsmatch is a good brand.
I have 2 Hawks, and always had mount creep problems with both rifles. Cheap or even averagely expensive mounts with a heavy scope creeped. There is no retention stud on the Hawk, so a one piece mount is really the best way.
On the foresight, I have removed both sights as I always use a scope. Its a large unit, and I found it interfered at low magnification, so do not be in a hurry to replace.
Candocad.