Stefan,    6260 should be an early model. Does the guitar have a "zero" fret? That is a fret very close to the nut (approx 3/16th inch. That is a good clue that it's an early one. Most early Sigmas will have the adjustable bridge but not all,depends when the stocks ran out and where it was made. I will take a fixed bridge anytime over an adjustable. As Iv'e said before, the only consistent thing with Sigmas is inconsistency.

Cheers, Neil