K&E 4081-3 ---- 1939-1947 Scale Set
This edition has the "KEUFFEL&ESSER CO.N.Y." name over 0.2 on the L scale. This location of the name probably was for a short period of time. These rules are sometimes confused with the earlier version with the LL00 scale on the top when viewing poor descriptions.
This rule is interesting in that the original purchase receipt is with it. This puts a hard date on the rule.
From the collection of Clark McCoy
Top edge showing serial # and original owners name
Front and back of case
Original purchase receipt
End of box