I think Mauser filled a 1943 order from Portugal. Maybe Kurusu knows the date for sure.

They were able to do so without disturbing delivery schedules for Germany, so maybe the Germans weren't acccepting more Lugers by then. Mauser was also making P-38's, and those were probably preferred.

Later, Portugal also used P-38's, but I don't know when they were acquired. Again, Kurusu is probably our best source, as he is Portuguese.