There are 3 periods:
1/ The Vintage Era: 1936 / 1983.
2/ The Pre Vendome Era: 1993 / March 1997.
3/ The Cartier Vendome Era: March '93 till now.
If you want a Pre V, I fear, Graham, that it's a bit too late...The Value of any Pre V Watch has reached the sky...
Best.
nicolas