Have I been sold the wrong watch

[mcilwain]

I have today purchased a Submariner 16800 which is suppose to be of a 1982 model from an AD in London, however since getting it home i'm not sure i've been sold the correct watch.

I spent many hours researching this sight for helpful ideas to making a purchase, however as soon as I started raising these questions the AD just dismissed this type of site as people who where not dealers but enthusiast.

It came with the paperwork which shows the date of purchase as 19/1/82.
The green wallet, watch case and guarantee show a serial number 0f 645****,
The model number on the guarantee is a 16800.

I queried the serial number with the AD as I thought it should be a 7.2 -7.75 million serial number , to which he replied that Rolex originally said that the 7.2 - 7.75 million was from that date but changed there mind due to unauthenticated record...

In addition the bracelet and clasp has been changed, which I was told but the only number I can see on the strap is 78360 on the clasp (no year or month marking) and 78360 on the bracelet wit 501 B on one of the ends as well.

I was under my own pressure to come up with the watch as buy son is getting married next Saturday and wanted to get him something which was special and he could enjoy. I had only seen one other but that had a lot of flex on the bracelet.

Any thoughts or help would be much appreciated.