I'll throw a monkey wrench in here...maybe this frame with lower weird "pibb" (I call em' nubs when used for shifters) and the accompanying rare/odd clamp were designed for a Suntour reverse action/ bottom pull/bassackwards front derailleurs like the SL and early XCs (I don't know about BLs like on this bike). On these reverse action derailleurs cable tension is used to pull chain down to smaller rings, a force much greater than spring tension (standard action derailleur use the spring tension for down shifts). If this is the case, above the pibb might be correct.