FabR[Senior Patek Moderator]
26166
Except that we had of course a few 5124 dials and metal colors, I honestly don't recall anything relevant re differences in production (but I can go back and see if I have something more, as I bought mine as one of my first Pateks, in May 2010 :-)
An interesting thing in my view was definitely the beautiful shape movement, unlike earlier Gondolo iterations with round movements (which you'll easily identify by the closed case back ;-)
Cheers.