Surely not, who had worked on the watch must have discarded the broken piece when the repair was not made.
A broken mainspring is easy to diagnose from the outside because the watch winds effortlessly and forever. You would then start work as a repair, not just servicing.
ORIS generally signs on the barrel bridge. Bentima, Novoris and Vertus , shared some parts and movements with ORIS, your watch can be any of brands mentioned.
Bridge layout might help as well.