I don't have them in front of me at the moment, but ALL pieces of bird glass were manufactured in one plant, in a limited date code range Oct-Dec 1967. Both tinted and clear glass were made, and this glass was installed primarily in Lordstown cars built 11/67-mid 01/68.
The glass found in later cars and earlier cars still bears date codes from this range of dates, and is virtually guaranteed to have been installed at some point in the car's post-delivery history.
Vikki
1969 Goldenrod Yellow / black 400 convertible numbers matching