Silver Supporting Member
Trying to make sure I know what I have. Serial number is A09309, which is not falling in the range of serial numbers that I've looked up. Its either a 66 or 67.
Take a flashlight and find the codes on the transformers-read them or post them here. Also, check the speaker codes (and pot codes if you want to take it apart), those factors are probably more accurate than the SN stamp.
There's another code on the speaker somewhere: 220yww or 220yyww, however it's likely those aren't the original speakers as Fender rarely used Jensens by 1966.
Since all the transformers were born in mid-66 (606yww), a late 66 construction date seems likely. There are no absolute guarantees and Fender had stuff lying around, but that's the closest you're going to get. Tube charts and serial numbers are probably NOT as accurate as date codes.