A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ronald van Riet
Date: 2016 Feb 19, 01:40 -0800
I am sorry to disappoint you but this is definitely a post war version, probably from the 1960s. It is not the one he must have used in WWII, those were all metal.
There are millions of E6B slide rules like these around, its value to you in memory of your father is definitely much more than the five or so dollars it could make on eBay.
Ronald van Riet