Watch looks gen to me, had that same series sub in TT blue a while back, price is good for a private sale but I wouldn't necessarily say it was a short-sell, after shipping and service your back in grey market numbers.
I also have a 217 that came with a black croc 26/26 with screw-in buckle with paneria off center engraved.
But then I bought the 47mm sub's black rubber strap and that one is 26/24 tapered and also has a screw-in buckle with panerai engraved in the center.
I know the gen panerai rubber straps on the 47mm subs are also tapered and DO have a gen 24mm panerai engraved buckle, just like the one that comes on the gen 194, 225 and 187.
Check the links for proof:
http://cgi.ebay.com/Panerai-PAM187-47mm-Ch...1QQcmdZViewItem
http://cgi.ebay.com/Panerai-PAM225-Slytech...1QQcmdZViewItem