I need some help with my Rolex Submariner

[dascenzo.nicola]

Hi guys, I purchased a Rolex Submariner yesterday which is supposed to be a 1994 14060M W serial.

I trusted the seller so I didn't ask him to remove the bracelet nor the case to check the movement.

I took the bracelet off this morning and I noticed that it was a 14060 reference on the case.

The question is : is it a mistake from them or Rolex didn't write the M until a certain year ?
Well, I am a bit confused because the 14060M was introduced in 2001. This sounds a bit anachronic.

Thank you very much.