GB transfers almost certainly won't be a good fit.
I have some at home, so can do a measurement for you after work. The key thing isn't just the shield diameter, it's the size of the shield boss, which, from memory are large on West Wind models. Also, some of their shields are flat, others very slightly 'dished'. The latter are not quite so good for transfers although they'll still work.
You could, of course, email West Wind and talk direct to them. They are generally very helpful folk...