Crown can tell you what the Model Number is, based on the Serial Number.

I worked at Crown for a long time; the machine that your working on is an FC; the "40" FC is a 4,000 lbs. lift capacity & the "50" is a 5,000lbs. lift capacity fork lift.

Not all Crown Field Branches are the same. Some are more professional than others.

The problem is that these plates are gone but I do have the serial #. Does Crown have a decoding system?

9A104 is almost always related to Crown 40 FC -or- 50 FC.

The Data Plate for the 40/50 FC is located very close to the Power Disconnect Handle (painted Red).
When you are sitting on the Operator's Seat, take a look at the Chassis Wall that is near/behind your Left boot; that is where the Data Plate is.