chug posted:There is a cutout partially visible in the picture of the power connector track that I and my friends assumed was for the power plug.
Eric Hofberg
Eric,
I assume that cutout is for the Low voltage controller (Schwachstromregler); see also this set:
And here two pages from the 1930 BING traders catalog (in three languages (but not English ;-(); the low voltage controller can be seen in the second page (just above my finger).
There is no mentioning anywhere that transformers were included in sets, but however it might have been different for export to the USA.
There are two German websites with further information on BING table railways; with Google translate it might be possible to understand these:
and
http://www.spur00.de/bing/bing.htm
Regards
Fred