Colin:
I hate to say it, but I am fairly certain that this one is a fake. I don't recognize any element of the chronograph as being by Heuer -- case, dial, hands, etc. -- and the marking on the movement is typical of a marking that is often applied to the fakes in South America.
Sorry about that.
Jeff
++++++++++++++++++++++++++++++++++++++++++++++++++
: Hello Forum, I have recently purchased my first
: Heuer chronograph, it is a vintage 2 reg.
: val.7734 mov (marked HEUER) The case back
: says "skin diver 20 atmospheres"
: and has the # 68503. I would appreciate any
: help in identifing the model, date of
: manufacture etc as I cannot see another one
: in your lists. I think It has too many
: genuine markings to be a fake, but I am not
: an expert of course.
: Best Colin Gillies (Bonnie Scotland)