Currently, on the cataloguing/addbooks.pl page, one can search for records in the catalog and the reservoir; starting from an empty record, one can also access the Z3950 search at cataloguing/z3950_search.pl But one cannot do a search on catalog + reservoir + Z3950, nor on reservoir + Z3950. That would be helpful for searching external records while doing acquisitions.
Proposition works as follows.
One still starts by selecting a vendor. But on acqui/basket.pl?supplierid=X the search menu is more complex and allows for a search on catalog + reservoir + Z3950. Search fields: Author / Title / Date / ISBN
Bellow are several tickboxes: catalog / reservoir / Z3950 target #1 / Z3950 target #2 / Z3950 target #n
The search runs on the selected targets. In the results list (acqui/neworderbiblio.pl):