K&E 4080-3 ---- 1939-1949 Scale Set 1st Edition
From the collection of Clark McCoy
There are 3 variants with the 1939-1949 scale set. They vary in the printing of the K&E name, the patent numbers, K&E logo, and extra marks on LL scales. The first one is shown here.
The "KEUFFEL & ESSER CO. N.Y." name is right after .2 on the L scale.