Pretty sure of the shelf, i found the mechanics on reverb saying it was rockinger abm hardware from the 80s. The circuit board has a tiny logo on but i couldn't find anything related to it.
I bought this headless bass used and the seller didn't have any information on who built it. He said he bought it as a Status Bass. But there is no markings whatsoever on it to identify it. So it might be custom built after all. All i found is that it supposedly uses Rockinger ABM mechanics form...