The Bisley hammer has a larger hump on the back,so won't drop into an SBH gripframe,without modifying but is otherwise compatible and of course,having the Bisley gripframe solves the hump problem.Fitting the gripframe normally would also involve blueing or re-blueing it.Sorry I don't have a name for you but about any decent revolver smith who also blues,should be able to handle it.
The grip frame is first installed on the gun and often the flat sides,where it meets the gunframe,are a tad wider and need to be reduced,by filing.Then,where the "ears" meet the gun frame,either side of the hammer,these need to be filed down slightly to match the gun frame.On a SS gun,you could file and sand while it is attached.
For a blued gun,you would scribe,remove the gripframe,file,reattach and check.Repeat the process till all matches up.Then the gripframe needs reblued.New gripframes are cast slightly oversized so this fitting can be done.A used gripframe would have been already fitted to someones gun and you might get lucky and have it fit your gun or be close.If it happens to be slightly smaller than your gun,the filing would have to be done on your gun's cylinder frame to achieve fit.
I believe,new grip frames for blued guns come rough cast and in the white.