Question about the machine heads. Are they factory standard? These seem to have ' slits' in the top part. Which I have not seen on any 6 bolt Silo picture I've seen
I'm pretty sure a 1992 Silhouette would be 5 bolt, not 6, so this I think is earlier. The first Silhouettes were 1986. Get the serial number and ask Customer Service.
The tuners were I think always Schallers. If they have slits in the top part, they may have been changed to vintage Kluson-style tuners, or some sort of top-locking tuners like some of the SUB1 guitars had.