Mick it's adjustable for offset, it does sit near dead centre to suit my face.
I've progressively deepened the thumb up groove, Ive found it helps with stability a touch.
It's also grooved the left side for thumb through/round position ..
Thanks maddog it's been a labour of love.
This is the underside of the fore end.
There's a matching chamfer on the walnut to follow the Ali anschutz rail.