bbforks,
unfortunatly i've seen this before with yale trucks and even hyster trucks where they do not stamp the complete serial number on the truck. Why they do this i have no idea but it does make it more frustrating when it comes to getting parts or service information by serial number.
The dealer should take that number and submit it to the mfg engineering and have them translate it to the full number.
All serial numbers on any yale or hyster are 10 digits
the breakdown is as follows:
D203D8919X (sometimes there will be 11 digits depending on the production sequence number.
-first letter and 3 numbers indicate the truck unit code
-second letter indicates the plant of manufacture
-the 4 or 5 digit number indicates the production sequence number
-the final letter indicates year of manufacture starting with "A" in 1957, 1980, and 2003. Letters "I", "O" and "Q" will not be used.

So i would suggest insisting the dealer contact the factory engineering team to decode this number you have from the frame.