I thought this A-9 jacket deal made me think of something...
http://www.godarsinc.com/ww2-us-army-air-forces-type-a9-flying-jacket-p-164.html
IIRC, on the TFL forum, the conclusion was that it was a repro with a wrongly colored shell they covered with a "rare prototype" story. the plot thickens!
I think the A_9 label as I've stated happened, but was nothing more than a mislabelling. It appears to be made otherwise to the B-10 Specifications. I'm gonna try and dig up some more period dark cloth examples of B-10 to B-15a. I need to check what was posted on the other thread when Im not on my phone. I'll start with the Roughwear B-15a, which they were able to qualify with an orginal. The point being that the colour Aero have chosen has precedence and offers something a little different.