Resources to learn more about 16710 and other GMT II

[In-N-Out]

Hi I have been looking to purchase a 16710 for a while now, but I'm open to other GMT II's.

Wondering how I can best educate myself in terms of what to look for:

1) Serial for the watch and the clasp (making sure they match)
2) Dial
3) Hands
4) Box, papers, tags, pamphlets etc

Where can I learn about each reference / serial in detail to make sure I am getting an all-original, period correct timepiece?

Thank you