That's a good story.
The bike was actually released in 1991 (At least in Europe). Then in 1994 a restyling.
In 1992 YMF"Sonauto also did a Marathon version with 37ltrs double aluminium tanks.
And around 1994 a XTZ660 R, also from YMF. This raced '95, '96 and '97 Dakar
And the more known '92 660 BYRD from Italy. One of the riders was Fabrizio Meoni. This bike had 63ltr tanks
Even Ohlins's first 2WD was a XTZ660.
Peterhansel also raced baja with a moded 660 without the front fairing.
But the most important, Ewan and Charley went training to AUS with two of these bikes
(Ewan's guffaw alert!)