I goto KL & Singapore very often for business trips. Frankly speaking I don't like the reps in KL China Town. Having said that, I have purchased a few Gen dials/ bracelet from a Ebay seller in KL with good success. That seller/ watchmaker would not want to meet me in person however ( i wanted to pay in person and probably want to get other things when I am in his shop). BAck to your questions, My friends in KL seem to get their watches from internet discussion forums (or from Andrew/ Josh).
Recently I was informed that there is a very watchmaker in Singapore who does franken Rolex & Tudor (SnowWhite and Daytona 6263). I would love to find this watchmaker.
Other that that, sorry I don't have any other useful info.