or unit fabricated. Air Force for example , every base that had aircraft had a sheet metal shop , we made most of our adapters and small mounts in house, It was called Local manufacture, The T.O would hava diagram or brief description and you made them from that, Many times UNITS determined where equipment went on vehicles, We even did this some what on aircraft. Local Mods didn't need higher HQ approval, Just you Wing CO. Army seemed more worried about careful placement on trucks than we ever did !