I have one. It shoots really good and straight. I built it from a kit- if you are going this route, plan on spending months working on it, and it won't svae you any money over a finished rifle.
The kit has all inletting done on the stock, and from what I can see, it is more of an assembly and finishing job than a "rifle building project". This one took me six months, built from scratch except for the barrel, which is from Green River Rifle Works (now located in Australia....)! Cal. 58 - shoots the Lyman 57730 570-grain Minie ball with 120 grains of FFg real well, as well as a .570" patched RB w/ same charge. 1/60" twist.
Cherry stock, silver mountings, fixed sight. POI @ 100 yards for Minie and RB turned out to be the same, for some reason???