Hood hinge date code
 

I need to have a set of hood hinges rebuilt on my 74 Formula and I have a few sets with different codes on them.
Does anyone have the magic decoder ring to decipher the numbers on the hinges?
I did a search on the site and couldn't find any information pertaining to hinge date codes.
The two that I "think" were original to the car have a 5 digit code of 30409 & 30412.
Any help is appreciated!
Thanks