Originally Posted by seagrade

Very interesting. Among thousands of Columbus tubing decals I can’t recall ever seeing one for a hybrid tube set (although seen hundreds for Tretubi variants) such as SLX-SP. Certainly frames were regularly custom built with mixed tubesets, I had an SLX-SP frame which may have had 531 chainstays, but the tubing decals didn’t reflect this. Heavier grade down tubes and chainstays, and occasionally top tubes, were often substituted, but if this was the case for this Masi the only true SLX tube left would have been the seat tube.

Also relatively unusual for SP to be involved in a frame as small as 54cm. I must look back at catalogues of the era…