Join artifacts and finds
After some discussion we decided to join artifacts and finds. They already have the same CIDOC CRM class, share the same standard type, overview and so on.
Only difference is that a find is an archeological structure and connected to a strategraphic unit but this isn't worth to handle them as separate classes.
For the end user it will be just a change of labels (finds are than called artifacts too) and it will simplify the model in the backend.