L625

It's the 25th Paramount frameset scheduled for production in November, 1966. It was probably built to 1967 model year specs.

From "Dating Your Paramount" on the Waterford website:

The First Serialized Date Code

This system was used from January 1966 through 1969. It consisted of three components -

• Month Code: This one letter code corresponds to the month with A=January, B=February and so on. Because I is not used, September=J and December=M.
• Year Code: This one digit code is the last digit of the year - 6 is 1966.
• Sequence Number: This two digit number represents the nth frame and/or fork scheduled during the month.

For example, H763 is the sixty-third frame or fork scheduled during August of 1967.