For later reference:
NASA-issued Speedmaster chronograph details ( SEB + CF partnumber + NASA Serial Number S/N )
The Part Number had specific designation with “S” the first letter for NASA, the second letter is the type of documentation or engineering drawings on record, with “E” for assembly drawing.
Other examples are: “L”= Source control (e.g., manufacture's specification) or “K”= drawings in book form. The third letter initially stood for the supplying division, “B” = Crew Systems or “D” = Space Physics, however, following the Apollo programs, this letter came to stand for the mission program “B”=Apollo, “C”= Skylab, “F”= ASTP, “D “= Space Shuttle, “Z”= multiprogram.
The caseback of the present lot is engraved SEB12100039-002, designating it as a NASA Speedmaster with engineering drawings on record supplied by its Crew Systems division.
While the present watch was not flown on a space mission, it was used for exercises for the Apollo, Skylab and Space Shuttle missions prior to being sold as surplus. The watch is accompanied by two Omega extracts, one signed by James H. Ragan, who was a NASA Program Manager and an aerospace engineer. The extract confirms the watch was delivered on December 6, 1968 to NASA via Norman Morris, Omega’s US distributor at the time.