Any one suggest good resources for Thai stamps? I may restart my collection of 40 years ago
That is a broad question, hard to advise. You need to determine what you want to collect eg : Classic >1940 or beyond. Then, what do you have remaining from your earlier collection. Do you want mint or used? etc & etc
Avoid ebay singletons, they will burn you. Try buying collections, (ebay) that is the most economical, there is a fellow that sell's collections cannot recall his name right now "dan stamps" ? Buy a collection, pick the stamps you need and sell back the rest, may be the best route. You need a target of about 25% of scott, more for the pristine or scarcer issues.
I have a smattering of Thai, but I have not begun to mount yet, I lived in Thailand for 5 years, I collected a few from street markets, but the humidity there was so bad, I stopped till I got back home.
There is a dealer on eBay named stampyboy, who presently has a few Thailand lots listed. Several are the 1920 era semipostals (Charities) overprinted for Scouting with the tiger face. Many are faked, but Stampyboy has both real and fakes for sale, as well as a very extensive Scouts on Stamps stock.
Stampyboy (Richard) is also a personal friend of mine and I have dealt with him--mostly buying--for many years through our local Stamp Club here in Cobb County, Georgia.
I have personally seen Stampyboy's vast stock (he's been selling on eBay for many years, with a 100% positive feedback score of 9738) Just last week I saw a massive accumulation he was selling, including many of the genuine, pricey Thailand Scouting charity issues.
Here is a great website which helps identify the faked Thailand Scouting overprints here: