Hi Everyone.
I'm a long time browser, first-time poster.
Looking at buying my first vintage watch, and am really interested in the Carreras of the early 70's.
I have seen one for sale, and it's described as being a 2nd generation case, with 1st execution dial, and 3rd execution hands.
The seller is the first owner, and claims that this is as originally purchased.

Being new to it all, I still find it a little confusing that some watches were made with combinations of both early and late features, rather than having disctinct "series" or updates, as cars do, for example.
My question is: Is this seller full of boloney? Can you have a 2nd gen case, with 1st exec dial and 3rd exec hands? has it been modified and tampered with? or worse still, is it likely a fake?

Any other tips for a novice, who doesnt want to throw his hard earned money at something that's actually not worth a fraction of the asking price, to those in the know...?

Many thanks in advance,
Josh