Here is a list that was graciously shared with us
that may be useful in your research of electric clocks,
both American and European:

Standard Electric School Master Clock
(click to enlarge)

STANDARD ELECTRIC TIME CO.

SELF WINDING CLOCK CO.

INTERNATIONAL TIME RECORDER/ITR/IBM/SIMPLEX

BLODGETT CLOCK CO.

ECO MAGNETO CLOCK CO.

GENERAL ELECTRIC and TELECHRON

HAMILTON-SANGAMO ELECTRIC CLOCKS

NEW HAVEN WESTINGHOUSE

HAYDON SESSIONS CHRONOMETRIC

VARIOUS MAKERS

BRITISH AND EUROPEAN MAKERS

ADDITIONAL LINKS (FOREIGN)