That's neat! I like seeing stuff like that even if it's not an intentional match pair. It's kind of like "father and son". My watchmaker friend told me that case I have was a "half pair" case and quite rare because of being gold filled and 18s. I need to find a good reliable source that lists the insignia on mine to tie down the maker, even though mine is written on the ring.
All makers did not put their name inside the case and went by the markings in it. Those who stick with it isn't what you think it is unless it says so in the case, aren't paying attention to men like Ehrhardt, Meggers, Shugart and others who had a wealth of information and have now passed on.
I will also add Terwilliger to that list because he had more information on torsion clocks than anybody. I have also found that men like Passmore grouped clocks together just because of association which never should have happened. I.E. Shatz and Jahresuhrenfabrik. Shatz in the early years worked for Jahresuhurenfabrik before branching out on his own with his grandsons creating Shatz manufacturing. Jahresuhurenfabrik is one of the earliest torsion clock makers.
Raymund L. Brown
"Associate with men of good quality if you esteem your own reputation; for it is better to be alone than in bad company".