Hello Golgo11,
Wilkommen to the Aerodrome!
I am not able to answer your question, but one of our Experts should be able to.
I see that you use "Jasta(s)." and remembered having a discussion with Author Darren Whiteside ""RAMPANT LION" The Life of
Eduard Ritter von Schleich * The Black Knight of Germany * WWI" on his use of Jasta as plural rather than Jastas. He replied that he had discussed this with the noted Author and WWI Historian Rick Duvien and that they both concurred that Jasta was correct for both singular and plural. Of course you will still see me use Jasta and Jastas!
Old Dogs are hard to teach new tricks!
Best Wishes, Jay aka
FOKKERJ
P.S. If I'm wrong, I challenge Darren to correct me!