While you have good reason not to like the idea of foreighn rule in your country, i don't think there is something bad about knowing that it was part of the history, and aknowledging how the neighbours (and occupants) influenced the development... (Trying to say: just because the Uniforms look similar to Russian, does not mean it's a bad UU for a free Latvia)... I.e. because Latvia spent a lot of time under foreighn rule in the one form or the other, it might be difficult to find a 'completely clean' UU...
There are two other things i can think of - both with some 'foreighn taste'...
Some kind of Crusader/Knight - The Livonian Order originated somewhere in the Area... (After the Area was 'introduced' to Christianity by Teutonic Crusaders...)
Another possibility would be some kind of Hanseatic Ship - like a Cogge - while the Hansa did not originated there, Riga was part of the Hanseatic League and became prosperous and influential, becaosue of it's position as a importan harbour. So i guess these ships were seen and used there a lot...