Dear Fred,
Yes, Chatuchak is the biggest weekend market in Thailand where is the rendezvous of all wholesale and retail antique sellers.

I don't know much about ancient bead dealers there but I am sure we are able to find the genuine one among plenty of replicas; also the Buddha amulets but there is only 3-5 percent which good. The remaining things are reproductions or even something called "set up" which never really been found with many long tale stories.

Lastly, I would like to thank you very much for all useful information and especially for your friendliness.

Cheers!

Paul