Introduced in the late 1950's to early 1960s, the 55 bent Dublin shape was created by none other than Sixten Ivarsson. On the bad side of the coin, as close as I can tell, the 55 shape hasn't been produced in eons. On the good side, it lives on in the form of the cool Stanwell registereds of yesteryear. Yep, pretty much like this one.
R. 'Bear' Graves