Lithuanian pocket watch by Jonas Karvelis

Been hiding in a cupboard for a long time, my great grandfathers memory, his personal watch. Date of making is not visible, do not want to tear it down just for that. Made/assembled in 1930s. The whole story is, that it was assembled by Jonas Karvelis, who collected Swiss watch parts and put them together. Do not know if there are more of these, or is this one of a kind.
Has written:
Jonas Karvelis (The maker, assembler)
Kaunas (City in Lithuania)
Amazingly still beating :)