For the GMT Experts....

[finance21]

A gentleman in my area is selling his GMT I on original Rolex jubilee bracelet with the red/blue bezel. The seller does not have the boxes or papers however; he does have the paperwork from getting the watch serviced about 5 years ago at an AD in the area (who then sent it to NY for servicing). Now, I have not a clue why he is selling a 20 year old GMT perhaps he is not a watch guy, I really don’t know.

Problem is this, I am interested in checking the watch out and making an offer but I honestly have NO idea what this should be going for. Without box or papers and without the older gentleman knowing the serial how I could get some info on this watch? Additionally, provided I do get the serial info is this something worth buying at a good price? What would a good price be for something like this?

Any GMT experts out there who would share their thoughts? Thanks!