With that done I turned to the grip cap as that will demarcate the wrist size for the shaping of the butt stock.
With a piece of buff horn trimmed to shape (1 3/4x1 1/4) for a slim grip

a rebate was filed round the edge

and then it was radiused over the top

after which a sand to clean off the file marks.

The holes were drilled for the 2 little brass dowles and it was epoxied into place.