Xoutpost.com - Timestamp Location

Where exactly is the time stamp on the headlight that can be referenced to see what type of sealant was used. So far I have found three. One is on the weather stripping another is on the back of the headlight housing and the last one is on the lens. All the dates are different. The one on the lens says 2/2003 the one on the housing says 1/2002 and the one on the weather strip says 12/2002. Can this headlight be opened? Any advice would be appreciated.

Thanks,
Adam