T206's larger than the standard 2 and 5/8 inches x 1 and 7/16 inches certainly do exist. They're not particularly uncommon. Fewer drastic examples exist today than there were 20-30 years ago, because some enterprising scam artists realized that if they bought a jumbo T206 in VG condition with soft corners, they could transformer the card from VG to NM condition by trimming the card down.
A board member, I forget who, did an exhaustive study of T206 sizes maybe a year or two back and published his results here. Edited to add: I found one such study and linked it below. I think others may have done a similar survey.
http://www.network54.com/Forum/15365...359/T206+sizes
p.s. And yes, for anyone on the board who is new to T206's, the Keeler pictured above is a reprint.