This movement looks very similar to a step down Omega 19 lignes : simple regulator, matte finish ... I got the idea that this was a "cheap" version, made while the 40,6 Robust was brewing, so somewhere between 1894 and 1923. Could it be?
Incidentally my watch has the "omega shaped" hands, one damaged, and a Dennison Star GF 0 Years, badly brasseed, and works perfectly.
Thanks for your condiderations and help