I don't believe there are any examples of butted maille of european origin from the time when it was actually used as armor. There are some types of asian maille that were butted and some 19th century pieces from India, used more for costume than protection. I'm working from memory here, so I may be mistaken, but I'm fairly confident that all european maile from the dark ages through the late medieval period (when it was actually used for protection) was all riveted or made of alternating riveted and solid rings. There is some debate on how the solid rings were made, either forge welded or cut from flat sheets, but they are very solid and have no seperation at all. Riveting and/or using solid rings is really the only practial way to make it strong enough to hold up in combat. Even today, with our modern materials, to make a butted hauberk that is strong enough to withstand actual use, you have to use 14ga. wire or better, which makes a hauberk weigh about 30-40 lbs. Period examples made with thinner, flattened, riveted rings would weigh about half as much. For a some good info on maile armour go here:
http://www.forth-armoury.com/research/research.htm his fellow also sells reasonably afordable, very authentic riveted maille armour, the tools to make it yourself, even "starter kits".