Here's a beautiful Bartell 12-string pic I found at a dealer's website.  Unfortunately the guitar was already sold so I couldn't get any better pics or info.  The headstock is identical to that used for the 6/12 doubleneck also featured on this site.  The rest of the construction is similar to the Bartell Spyder guitar except for it's use of a tailpiece instead of a vibrato.

Listed as: 1967 Bartell, XX12, Number 142 of 250 made. Rare!