Levi's Trucker Dates

[KOOLKERNEY]

I apologize for making a new thread for this, I'm new to the forum and I don't know how much of a no-no this may be. I have a big E jacket with WPL 423 on the label. I'm just curious of a more specific date than I have found previously online. Anyone have an idea?

 

[Baron Kurtz]

By trucker I assume you mean the 557(XX)

http://www.vintagemotorcyclejackets.com/chart1.htm