Good job...
Well said DCKD.......your information for Matt's question will help others too.
The HIN (hull identification number) is on the back, lower starboard (right side) of the hull. The last two digits will tell you the year of manafacturer.
The EIN (engine identification number) is located in one of two places. Either across the back, top side of the PTO casing or on the front at the MAG casing. It will be a metal stamp type.
If your looking at a used ski, the most important piece of paper you need is the years registration. There isn't another piece of paper more important than that one. Make sure the numbers on the registration match the numbers on the ski. Before a purchase, if you think anything is amiss or shady, go to your local DMV and they will run a check on it to ensure it isn't stolen.
I would be very careful about buying a ski/boat outside your state, since all watercraft are governed by state laws.
Good luck on your hunt. :cheers: