Hmmm, I dont think there is an answer to your question, cos the sl was simply a build option of the ss model.
The only place I have found which attempts to 'decode' the vin is:
http://www.ducati.net/faq.cfm?id=13 but it is by no means foolproof.
Remembe that the factory was (has !) never cash-rich, so always tried to use whatever stock they could get in, resulting in many bikes shipped with differeing specs, and even with parts that should have been rejected by quality control.
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