need advice about my daytona please

[floydpower]

I recently bought a ss rolex zenith daytona for £7000. It was a dream watch and i had to save hard to buy it.
The watch was sold as a 1993 model, but i did some research and found that it could not be a 1993 model as it has a luminova dial ie no letter t before and after the word swiss made. This means the dial is a 99/2000 model.
I am worried now that the watch is either fake or cobbled together although i did buy it from a reputable jeweller.
This raises a few questions,
how much is it to have rolex authenticate it and does it have to be sent to switzerland to do this. Will rolex confirm year etc if real.
how much will it affect value of watch if it is proper movement inside ie not a fake but it has had a dial change.
whats best site to date watch from its serial number.
Thanx in anticipation of help,