If you are crazy about vintage watches like me and you are looking some reliable vintage watches stores in Bangkok. I recommend " Because I Like It" located at the third floor Siam Center. I got Omega Speed Master Moon Watch cal.861 circa 1971 from the shop at very good price and very good condition.
Look for the owner" Mr. Pete" (he is very very nice0 and you will get full of knowledge about watches and may be you get some new old stock watches produced from 1940-1970 like Rolex, Omega, Hauer, Breitling and Zenith. He specializes in second hand chrono, vintage chrono , Omega, Rolex. pockte and character watches. Getting there is easy just catch BTS and go to Siam Center, get off at Siam Station.