vintage Slide Rule: K & E N4053-3 in CASE

vintage Slide Rule: K & E N4053-3 in CASE

vintage Slide Rule: K & E N 4053-3 in leather K&E case. Mahogany with paper conversion table. This model was from between 1936-1954 based on below catalog information:

1936 -- The improved metal framed cursor was introduced.
1939 -- Only the N4053-3, N4053-3F, N4053-5 appears in the catalog.
1942 -- Only the N4053-3 and N4053-5 are shown in the catalog.
1954 -- The model number of the N4053-3 was changed to 4053-3, the profile shape of the body was changed, and the conversion tables on the rear were printed directly without a paper label. The N4053-5 remained unchanged.
The case has slight wear but the slide rule is perfect with no knicks or damage.