2 1940's Era Keuffel & Esser N4081 Slide Rules N4081-3 & 4081-3 + Leather Cases

2 1940's Era Keuffel & Esser N4081 Slide Rules N4081-3 & 4081-3 + Leather Cases. These are Log Log Duplex Decitrig slide rules They are 1940's K & E slide rules with 1 manual. 1 has a cursor and, as shown, one does not.   The one without the cursor appears to be a bit older than the other one. Both have leather cases. One of the leather cases is relatively new and the other is more worn with the top flap turn off. Condition: both rules have some dust, light brown spots and residue.  They could be cleaned up considerably.  One of the cases is EX- , and the other is Fair.