[78-L] Questions on German labels

[Harold Aherne]

I'm rather curious about the years of production for Tri-Ergon, Vox, Clausophon
and Beka. The first three were active at least in the mid-late 20s; Beka was of course
a Lindström brand active in the early 20th century to at least 1929-ish. If anyone knows
more precise details, I'd be grateful for them.
 
Ultraphon, from my understanding, was in production in Germany from 1929-32
at which time it was replaced by Telefunken--I think. The label still existed in France
in 1934-35, when the Quintette du Hot Club appeared on it; does anyone know how
long the label was used there?
 
I also might as well ask about the Homocord label used in the later 20s; an example
is at http://www.lib.washington.edu/music/images/homocord.gif   .
What is the obelisk-like structure supposed to represent? (and of course, I know
I'm just asking for Freudian-inspired answers ;-), but it's certainly an attractive and
distinctive label). 
 
More info on Homokord/Homocord can be found at 
http://www.russian-records.com/details.php?image_id=3193 
(for corporate history) and
http://www.slba.se/03mediearkivet/documents/dating_german_homocord.pdf
(for matrix and catalogue series). 
 
-Harold