Thanks Kyrie.
Great explantion.
I just subscribe to the "simple" answer is usually the correct one.
One has to assume quite a lot of bits and pieces came together to get the Austrian connection, as it is not visible on the pistol itself; the added numbers could have been done anywhere and anytime IMO.
Whether or not the dished follower was necessary or not, it is present in many Red 9s; so many that in the past it was "assumed" that a Red 9 without the dished follower indicated a "wrong" follower. I'm talking 50 years ago of course, maybe this has been elucidated since then.
I collected Brooms long ago, and have not followed any new info that may have been gained in the last 40 or 50 years.
Thanks again for sharing the evaluation of the possible Austrian indications.