9204 Booster Question

[6667ss138]

I have always assumed that my power brake booster was the original for my car. My car is a 69 Z/28 built 07A, I decided to take some close-up pictures and the 9204 and 110 date look correct but there are some other numbers stamped as well. The 110 date was April 20th, 1969, which was on a Sunday which seems odd. Most all of the original components on my car are all dated May and June so the late April is a possibility, I guess. Has anyone ever seen the extra numbers stamped like this before?
Sorry for the upside-down pics, I tried to flip them but no luck. Any thoughts or opinions on the stamps are appreciated!