Mononoke key cels?

Is there a way to tell which mononoke cels are key cels? Is it the usual A1 then circled number "end". i read here that more than half the cels were done by key animators.
http://www.animanga.com/cels/book/archive1/p5886.html

An A1 would usually be a key, and any cel marked "END" (or sometimes something like "A12E" would be a key. But any extreme position in the middle, or one in which the character pauses for a moment, could be a key.

If you had the timing sheet or the gengas (keyframe sketches) that went with the cut, you could tell for sure. And if you can get the douga for the cel, that will have the sequence number in the corner circled, which was studios' shorthand for a key.

Failing that, you just have to use your gut. Some images in a cut are intangibly stronger than others, though this could also mean that the inbetweener artist (who also traces the keys from the key animator's genga) was especially talented.