'It's so irregular an individual that we all wanted to validate it.

'60s LEVI'S 501ZXX or 501Z
Kurihara:I brought the third one especially because I wanted Yutaka to see it. The patch is missing, the engraving on the back of the button is J, there are hidden rivets on the hip pockets, and the zipper is a Talon 42.



Fujiwara:It is certainly irregular. If all of them are transitional, there are three possible patterns: "501ZXX," "501Z," and "501Z-502," but I think the "501Z-502" line is thin in terms of specifications.
Abe:Why?
Fujiwara:The letters A, S, F, etc. on the back of buttons and on patches, so-called "typing patches," are all letters of the alphabet, but it has recently been discovered that these letters, which used to be referred to as quality, actually all refer to the manufacturing plant. It has recently been discovered that these letters, which used to be called "quality," actually all mean manufacturing plants.
Abe:Can you identify them?
Fujiwara:We have not yet been able to identify all of them, but we have been able to corroborate that they mean factories. Furthermore, we're gradually finding out that each factory had a different model and notation of what was manufactured there. We know that the "501Z-502," which I personally consider the line to be thin, was generally manufactured at the factory where the back of the button is stamped with K. In other words, when the back of the button is stamped J, there is a high possibility that it was made in another factory.

Konno:That's great. Does that mean that even if they are exactly the same age, the model name could be different depending on the manufacturing plant?
Fujiwara:That is not impossible. So, the model that Mr. Chestnut brought is most likely either a "501ZXX" or a transitional "501Z" because of the hidden rivets on the hip pockets, but the fact that the zipper is a Talon 42 is quite irregular.
Kurihara:Right?
Fujiwara:However, my personal opinion is that it is as close to "501Z" as possible, although the possibility of "501ZXX" is not zero.
Abe:It's a great and interesting story, but my mind was getting confused while listening to it (laughs).