Chuck, I believe the last engines to have the crank lugs were the early full pressure 235's - - -1954 and 55 1st. series. The large diameter dampers used on the later 235's and 261's are the ones I've seen with the squared-off center hole that a 3/4" drive will fit.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!