TYPE B-9???

Need some help identifying this jacket as I can’t seem to find much by a google search. Maker tag is hard to get a full photo of. This is what it says but can’t see. TYPE B-9 isnt exposed it’s sewn and folded under the naked tag. I’ll attach pics, very similar to the B15 in appearance. Had anyone ever seen one or have one out there? The B9’s ive seen are a lot longer and not cut like a flight jacket. I appreciate any guidance from the field.

TYPE B-9
HEAVY
SPECIFICATION 1208
CONTRACT 723...

TYPE B-9???