Help on this new ebay purchased year 2000 SD 16600

[FJY787]

Need some help.

I just bought a used SeaDweller 16600 from a private ebay vendor with 100% rating. He said he was the original owner and the box even has name and the phone # of the store where he purchased it 8 years ago in Connecticut. He did say that the watch was serviced but didn't specify.

After the delivery, I opened the case back to make sure everything is good. Several problematic issues came up and I am now panicking because $4000 may have been spent on a damaged or "tainted" SD.

First, there appears to be 2 etchings just under the serial # in the inner side of the backcasing. The etching appear to be some type of service code as in H746PR345, such and such. It seems to have been done by hand. The writing is irregular and could only have been done by a sharp etching tool. Only can read it with magnifying glass. Under that there is significant smudge or a stain about 2 mm in diameter, below the etchings


Second, a friend of mine who has more experience than me about Rolex says the the colored gears don't seem to match the colors with each other. They are sort of orange/yellow/purplish two gears turning to make the movements. Their color just don't appear to be alike.

In the exterior of the watch, it looks OK. the watch is noted to be 1-5 seconds slow in about 12 hours.

Should I have the AD look at it?

OR

Should I just try to return the item if the seller will accept it back. I can certainly tell Paypal people that it's not original Rolex.

Please let me know if you have any other suggestions.