Looking for any documentation '69 Barracuda Fastback

I'll be honest, I forgot to check for the torque plates.

I do believe it was built very early in the model year. Chrysler/Plymouth started the production year with serial #100001. My sequential number is 115705. so I believe it was the 15,704 car built. If I have the right info; 31,987 6 cylinders were shipped and 20,337 V8's were shipped for a total of 52,324. I need to research the production numbers. I'd really love to find out about what date mine was built. I haven't found out yet if there is anyway to compare the sequential number to a build date.
So I'm curious, does the casting date on the rear come close to the early build of the car ie last 6 of the vin? My vin is 305604 and was built 2.26 69