McDonnell construction #s for F-101s?

[Voodoo]

I'm looking for information on McDonnell construction numbers for F-101s.

I recently acquired an exterior aluminum panel which came off a CF-101. It carries a tag stating that it is off an F-101, part # 20-33024-9. Most importantly, it identifies the aircraft that it belonged to, as serial U20-391.

I'm assuming that 391 is a McDonnell construction number. Does anyone know a tie in to this construction #, and a USAF serial? Any information would be appreciated.

Thanks,

Martin Keenan