1970 Axle and Valve cover markings

Hi everyone... working on a '70 383 roadrunner with Automatic. I've got what's left of the build sheet trying to figure out what codes belong on the valve covers and 8-3/4 axle housing and center section. On the build sheets under axle, D is the number 56. Also, next to P/shaft is another axle section coded 052. Where and what/which get's stamped on the axle housing and the center section? Also, I can't find anyting anywhere that would indicate what belongs on the front of the valve covers. Thanks everyone!

My Lynch Rd 9/69 built 70 had a white oil paint pen "x" on the round part of the housing center and an orange spray paint dot below the fill plug on the carrier. I know the orange spray mark signifies limited slip fill. The x must be an inspector mark. I may have a documentation pic.

Differential color codes

THis should help with other markings

Page 2 of the article

These are the markings I reproduced on my (Lynch Road) Superbird 8-3/4 axle. As indicated in the previous article, you need to carefully inspect the rear axle to look for these marks before restoration since there doesn't seem to be any consistency.

a front shot