todmichel wrote:
I was totally unaware of this first version (by Sompote Sands) of the Krai Thong legend, I thought he only made/produced the 1980 and 1985 (?) versions starring Sorapong Chatree. Do you know who were the stars of CHALAWAN?  
Sorry but I don't who the stars of CHALAWAN were. The information that I posted above is pretty much all I know about it. I got most of it from a Japanese website that Chaiyo maintained that had a complete (or nearly complete) filmography of all their productions. Unfortuantely I can't find that website now and it appears that it may not exist anymore.

Here is a bare bones entry for the film over at the Thai Film Database which only gives the title (in Thai), a year of release, and a thumbnail reproduction of the poster you uploaded.
http://www.thaifilmdb.com/th/tt02865

Also I am not aware of any film adaptations of the Krai Thong legend beyond the ones you listed. However given the fact there is still a paucity of hard information concerning vintage Thai/Cambodian cinema available in the west at the moment there could very well be another version that has eluded detection.