Need help on Verifying First Rolex

[Afterlife]

I'm looking at buying my first Rolex and my friend, who works at a local Watch Store, is looking to give me a good deal on my first Rolex.

Originally, I was looking at a circa 1990, black dial, no box no papers and was offered the next day, the same price on a 1986/1988 champagne dial with box/papers.

I was really set on a sapphire crystal, and according to the listing, it shows sapphire crystal, but according to the 16013 serial, shows plastic.

I'm not sure if it's a misprint, but looks like same watch, one shows 1986 while the other shows 1988, is there a way to confirm this before I confirm the sale?

Shows sapphire crystal but 16013,
http://www.sarasotawatch.com/collect...nt=19630592134


Shows 16013, but 1988 & saphire crystal?
http://www.sarasotawatch.com/collect...nt=19630284550