Any thoughts on this vintage levis chambray?

[breakfasteatre]

Found this chambray thrifting, the tag and buttons are weird, but the shirt is otherwise well made, with alot of chainstitching (or similar)

thought the buttons to hold the pockets open was interesting, i feel like i recall seeing an lvc item with that rainbow patch.

Im guessing based on no big E and the white tag this shirt dates from the 70s?

all the buttons are embossed with levis as well

[Tyro1]

might want to post this in one of the levis / LVC threads in superdenim