The gold squares on the statue are pieces of gold leaf. I'm not sure of all the places where gold leaf is available, but have bought them at a wat (temple). The gold leaf is put on figures which are venerated, simply rubbed on, and over time the figures are completely gold covered. The fact that there are only a few squares on Mengrai, seems to me to indicate the statue is only new. I think Mengrai is pretty venerated. Also, people would have to bring the squares from elsewhere as I saw none available for purchase on the site.