This nasa.gov site lists the NASA #67 Speedmaster 105.012-66 issued to Commander Cernan for Apollo 17:
Omega Speedmaster Watches
Maybe he took the 105.003 as a backup? In any case, all evidence I've seen appears to indicate that the Omega Speedmaster Professional 105.012 was
the first, and the last, watch worn on the moon.
The 105.012 was also the most flown variant of Speedmaster by NASA during the 60's and early 70's:
Gemini 11
Apollo 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17
Apollo-Soyuz Test program
SkyLab 3,4
Given all this there is some considerable weight to the argument that the 105.012 is the most collectible Speedmaster for the space afficianado...