Faber Castell 2x 378 electro slide rule in case 1940 Germany

Combination of 2 slightly different slide rules with one card board box. In the 1940’s this were the need to have for every technical engineer, the 378 Electro. The rules and cursors are all complete and all in good condition with signs of normal use. There is some yellowing to the (original) plastic cursor insert, the other is glass. Both have small marks as additions to the scales. Both have a good condition metal fork on the slider. There is one original (numbered) cardboard box that is complete where a tear in the top end,  Both rules measure ca. 29,5 cm or 11 3/4 inches long. Check the attached video on how to work your vintage man tool: slide rule operation instructions!