The VIN on the plate for my 1968 C10 is only 12positions. All websites i've found to help decode the VIN require a 17 character VIN. What can I do?

I just found a site called VINWIZ.COM!! Problem solved!!

The 17 character VIN was not used until 1980.

VINWIZ,com only goes back to 1950 and then for only some makes and models.

Just an FYI. Not sure about your state but when I originally register my 41 I had to have a bunch of extra paper work because of the vin not being a standard 17 character one. Luckily I had a friend that told me what I would need and where to get it in advance from the DMV website. Unfortunately I had to wait for a teller that was familiar with the forms once I got there.