I have a Neumann m249b microphone from CBS NYC. The serial number dates to the mid 1960s. The inventory number on the power supply is CBS-13-059-0750 NYC RN. There is a sticker on the bottom from Gotham Audio Corporation. There is also a small piece of masking tape with what appears to be “B.6All.” written on it on the bottom of the power supply and “#3” written on the power supply in large black permanent marker on the top. The microphone has the same inventory number inscribed on the bottom opposite the small plate with the serial number. If anyone could help provide information on the history of this mic, I’d greatly appreciate.-j