More interesting information on the Elgin Electronics kindly supplied by John Runciman, FNAWCC from Chapter 50 Puget Sound, NAWCC. This literature (letters, booklets, articles) is rarer that the watches themselves!

In no particular order, first up are the pages from a Elgin Electronic waranty card / booklet that was supplied with each watch; it is dated July 1962. The booklet, when unfolded, was 3 pages wide.

An original Elgin W-1 battery from 1962, still in its packaging...sadly it has leaked, so it's a liitle difficult to see it. The last scan gives some information on Elgin's battery technology:

The Elgin letter below highlights the close cooperation that existed between Elgin and LIP in sharing technical knowledge while developing an electric movement. The second scan is of Patent No. 3,224,184. filed on Oct. 14th, 1963 and shows a movement close to the production Cal. 910 but still with a Cal. 725 style coil. It is intersting to note that the author of the letter, Carl N. Challacombe, is also one of the listed inventors on the Patent filing: