We've been 'round this subject before, but I don't think the 11 code on the crank arms had anything to do with warranty replacement parts. I had heard the same speculation, but it just doesn't seem logical to me. There are PAT 11 N-Rec rear derailleurs as well, which are last-generation. A friend brought me one from Italy, still in it's original box with paperwork. Not what you would think for a warranty replacement.
As for crank arms, there are late S-Rec arms, non-fluted, with both the engraved and etched logo, with the 11-in-square marking. I also have a pair of non-fluted pista crank arms, etched logo, with a 31-in-square marking. What's interesting about these is that the logo is centered on the arms, rather than being nearer the spindle mount, which is more typical. All of the non-fluted arms, both pista and strada, have a beefed-up profile at the crack-prone spider-arm junction.
Wayne Bingham
Falls Church VA