Subject: sighting: PBS ''The Secret of Tuxedo Park' documentary
A 2018 documentary on 'The Secret of Tuxedo Park' just aired in the UK on the fairly new Freeview PBS channel. It covers the life and work of Alfred Loomis.
As well as a multi-function SR shown in use later in the section on radar it was remarked that Alfred Loomis designed his own slide rule for calculating securities. A Google Snippet of a book by Jennet Conant suggests this design was rejected by the US Patent Office but also couldn't find an image of the design online.