I am glad you asked, it made me aware of a vin error on my moto insurance, had to get my title to double check it, anyway, lets say there was such a thing as a 1997 fx650, if i was using my vin as a guide it would go somthing like this....YU7FX6501V0002046 there should be 17 digits,
also i thought i may have read somehwere that the last of your vin number somehow goes along with the number on the right side of the cylinder, above the engine cc number
if you knew the previous owners name and state that was registered they may have it on file too, it would be worth the call and the easiest thing, or could contact previos owner
if it really mattered to have it you could always buy a tweaked old berg frame and cut out the number and tac weld it to but i am sure it doesnt matter that much they will just be glad to take your money and give you a sticker