DoubleD,

SDH is the handle of Steven Dodd Hughes. He is a custom rifle/shotgun smith and also a contributor here and on AR. He has authored two books out relating to fine long guns. The first is "Fine Gunmaking, Double Shotguns" and the second is titled "Custom Rifles in Black and White" They are both excellent books and I would highly recommend them to any fine gun enthusiast. SDH also writes articles for various magazines having to do with long guns. He recently had a couple of very good articles in Sports Afield about Custom Rifles.

A search for his handle here and on AR should bring up his posts/profile.