PPG Glass Date Codes?

[Mark_C]

I don't think that is correct:

My glass (04L Pace car) are coded as follows:

Drivers door: 26-29
Drivers Quarter: 27-29
Passenger Door: 16-29
Passenger Quarter: 27-29

My passenger door has no DOT codes on it which would indicate it was made before 1/1/69 since glass had to carry a DOT code after that date.

A wild guess would be that the first 2 numbers are a week code based on the production year. The first week of August would be 1, January 1, 1969 would be 23. The second one could be the assembly plant if there are 29 of them, or it could be plant no. 2 in year engine in a 9.