Hi, sorry for pulling out this old thread.
Just seen in Munich another old K2 Full Suspension. It was in pretty used condition but interesting nevertheless.
It looks exactly like yours, and of course like the Boulder cycles Deviant, but is is labeled as "FS-1".
That fits than also to information in older buyers guide from 1992 and 1993 listing a K2 Fully called FS-1 (but doesn't include pictures).