So I couldn’t quite find a grip that fit my had as well as I’d like, so I took a UTG sniper’s grip:
http://centerfiresystems.com/productimages/ar-15/AR-GRIP-UTG-D.jpg
And sanded the hell out of it until its contours were nearly identical to my Hk P30 (which fits like a glove) then proceeded to stipple the grip in the same (though slightly modified) pattern.
Here is the result:
Stippling was done with an angled needle-point tip of a wood-burner.