I've upgraded the 68mm bottom bracket on my '68 Competition with a 2008 cranket by flipping the spindle around, as suggested by Sheldon Brown, but it's still not lined up perfectly. The new matching bottom brackets come in 102mm, and seem to be pretty common (ie cheap)

Is that the right size? It says right on the box, for 68mm BBs. Or is there some other trick to this?