That blue 1991 version ?

So I counted the teeth and found the rear is in fact 13/15/17/19/21/23/25 so not 13/23 as shown in the German catalogue (unless my eyes are failing me). I must have the US catalogue somewhere in a box so I'll try to dig it out at some point. The FD is indeed 28 for the smallest and 50 for the big one and the second one is likely 42 (chain is on it so I didn't count it). Mine is a 58 frame (I'm 6'3") so I'm not sure how tall you need to be to ride on the 60 and 62 frames ?! It weight in at 11kg which is pretty decent for a bike that size .

Pretty good range in any case : 8.27m to 2.41m / 385%

Yep. The blue one is mine. At 6'-3" depending on arm and leg length, I would guess you would need at least a 60cm

Well I'm happy to report that my trusty 1991 DC Supercourse was a great companion this summer and let me climb my first passes in the Alps courtesy of the 28x26 granny gear ! Hey on a 10% slope at 90 rpm that's about 330 watts or 4.4 watts/kg for me, that's a lot ;-) In any case it was a terrific experience and I'm thinking I might want to get a modern bike at some point...