It's my feeling the images were taken from opposite corners because of the abundance of trees in the lower left hand area of the "old" picture and the trees in the upper right hand area of the "new" one. They were taken from similar angles, though (a lucky coincidence). I've done some cropping to both images, but at the end of today's post you can see my original color image from 2006.
This sort of thing always interests me but I haven't done much research for older Thailand photos so far. Today's 1946 image comes up on a number of sites, but without information as to who took the original photo so I can't give credit where credit is due, unfortunately.