As far as I can make out the bezel on the Mark 1 has 60 clicks and 120 on the Mark 2. I think also the crystal on the Mark 1 is mineral and on the Mark 2 is sapphire.
Not sure there are any other differences. Clearly on the 'Reissue special editions' 80 auto and 83 RN diver the bezel insert is a modern Bakelite lookalike and is fully lumed.