Indeed, I also think the current existence of the Thai version is highly questionable.
As for "The Crocodile Men", I saw 1972, 1974, 1976, and 1983 mentioned as the year of production.
It clearly looks like it was filmed in Cambodia (rather than Taiwan), which more or less rules out 1976 (Khmer Rouge era).
What would you estimate is the right year? I'd stick with 1972 for the time being.
1983 is a very questionable production year for a supposed-to-be-Cambodian film I think hardly any films were made in Cambodia at that time.