my rolex is genuene or not

[rajarya]

hi,

Recently I purchased a rolex watch daytona oyster perpetual with superlative chromograph. It has all the logos on strap and in watch ,also have logo in side the rim below glass where the rolex is written in circular manner.It has steel belt on witch no 16520 is engraved . on back rolex oyster original gas escape valve is written and ad daytona is written .on strap inside 78488 no.is written with geneve and rolex with 18K and 750.I have tested the strap from a gold smith and he vouches that it is white gold and on the belt is 10 to 11 carat gold and in side the strap where all information is written ,is 18 k gold.I have also made the testing in computerized lab for gold varification .after scratching the metal they have varified that it is indeed 18 k white gold. The watch looks absolutely genuene and functions like one.But I have taken it to two watch dealers and they (their sales person) said that it is duplicate. Another watch dealer ,with whom I had telephonic conversation told me that there are no logos in side the machine, if we open it.and he said that no body can say that it is genuene or not and only rolex service center people can find it out.He said that dealers are not authorized to say anything about it. I am highly confused. I want to know why a duplicate watch maker will use white gold in strap .The amount of gold may varie between 15 to 20 grams. It has such minute engravings and logos on such places that it is very difficult to see with naked eye.Why any watchmaker will take trouble to do such craftmanship.
I will be highly grateful for the answer.
Raj