53/39 might require a modern crank 'cause you'd have to have a max of a 135mm bcd to get that small on the little ring and most older cranks were bigger than that. As for the chain ring width and spacing, I have classic, 9-spd, and 10-spd cranks so I'm going to measure this when I get home but I thought the difference was just in the spacing between the chainrings so that for example, a Campy 10-spd crank would have the same big ring as a 9-spd and a small ring with thiner mounting tabs to bring it closer to the big ring . I thought the interior spacing of the chain is the same but the outer width has been made smaller through some hocus-pocus with the sideplates and rivets. I know I've read that with Campy at least you just change the small ring on your 9-spd crank and presto: a 10-spd crank. IF that were true then you could mill the chainring mouting tabs and/or mounting bosses to change the ring spacing for 10-spd. That might be more trouble than it's worth though.