Is the one on the Left an inlayed emblem?And, the right a screen print?Possible the left is a WENGER variant after Victorinox assumed manufacturing?
According to Urs Wyss from Victorinox, the tweezers were introduced in 1902 with a nickel-silver head, in 1957 it was switched to aluminium, and in 1978 the grey plastic head we see today was introduced.
https://www.sakwiki.com/tiki-index.php?page=Tweezers
Well according to our 91mm dating spreadsheet - The shield changed from NS to SS in 1980And if we assume that the 58mm shields and the larger to smaller shields happened at the same time - Then we may have an answer? https://forum.multitool.org/index.php/topic,51872.0.html