Hello Mark and Leon,
The info Leon posted is essentially correct.
Josef Jacobs apparently was very vocal in his disregard for the Nazis, even before Goering tried to muscle-in on his business, as was their practice. Al Capone was a kindergarten extortionist compared to the Nazis. Old Scarface shook down neighborhood businesses--the Nazis shook down entire industries, and this became the primary source of their wealth. Messerschmidt and Junkers are only two of the more famous examples.
Jacobs did move his business to the Netherlands to escape them but soon found the only buyer for aircraft components in the 1930's was Germany. He closed his business and returned to Germany in the late 1930's prior to the beginning of WW2.
For a time he came under the scrutiny of the Gestapo and the SD, but apparently they found nothing incriminating on him. Some have suggested that the Pour le Merite saved him, the same claim is also made for 2 of Josef's friends--Sachsenberg and Osterkamp. Possible but not likely as it did not save
Hans Klein, who was a Luftwaffe General when he was murdered in Nov 1944.
Jacobs did accept (perhaps was forced) a reserve commission as a major at the beginning of WW2, but did no combat flying. If he had been gracious enough to join the Nazi Party, he most certainly would have been promoted to General as were many of the PLM holders. Curiously enough his friend Theo Osterkamp was the only flyer to become an ace in both World Wars.
There is a Sanke-type Card depicting Josef Jacobs in his WW2 Luftwaffe uniform.
In the end Jacobs, Osterkamp, and Sachsenberg all lived long beyond the close of the "Thousand Year Reich". At his death in 1978, Josef Jacobs was the last surviving aviation recipient of the Pour le Merite.
I hope this helps...
Best Wishes,
Gary