Okay so I just finished watching the 1.66:1 version of Curse of Frankenstein, as seen on the newish Blu-ray, and was underwhelmed by how not bad the framing was. It looked fine to me. Sure, a handful of shots are fairly tight, but they don't look "wrong." It seems as if they were meant to appear that way. This doesn't look like a fullscreen-composed movie mutilated to 1.66:1, it just looks like a sleekly-shot 1.66:1 movie. And as others have noted in this thread, posting random screencaps with heads nearly cut is misleading and says nothing about how this version looks in general, and it's quite common to see heads get a little trimmed in movies anyway. The new kids running Hammer may insist that the movie was originally fullscreen, but at least they gave us an option to view, presumably, the accurate framing. Just wanted to offer my two cents for anybody who happens to read this post.