Manufacturer's logo --- help needed

[RA3CC]

Need help in identifying manufacturers who made the following samples from my collection:

(1) Amtszusatz fur den kl. Klappenschrank zu 10 Ltg.



Manufacturer's logo looks like that:



BTW what the "trop" may stand for?


(2) Feldmesskästchen



Manufacturer's logo is poorly visible:



Maybe the next drawing helps:



Thanks in advance -

Valeriy, RA3CC

[Funksammler]

R B & Co = Richard Bosse & Co, Berlin
I don't recognise the GR1888 logo...

regards,

Funksammler

[rv12p2000]

Hello

Some informations about German telephone factory

http://www.henderson-tele.com/vtm/de/de/makers.html

Regards
RV12P2000

[Val]

Feldmesskästchen hersteller logo is easy - Gebr. Ruhstrat, Göttingen.

http://www.historische-messtechnik.d...at-gebr-ag.php

[RA3CC]

Feldmesskästchen hersteller logo is easy - Gebr. Ruhstrat, Göttingen...

Thank you very much, Val !!