Mallard,
go for the butt weld or the joint with a small gap, I prefer the butt joint, a gap of any size will cause more distortion, a nice tight fit is best but you dont want the two edges pressed together with any pressure as this will also cause distortion.I agree with the others on the overlap, it just invites moisture and rust.as for GMSea's questions on the braze.stay away from that stuff. for one thing paint doesnt stick to it to well and alway manages to create rust around the brazed area. and the fumes from brass are real nasty and will make you sick in a hurry.
