I have been studying Moe Norman's swing and I believe that there are many inaccurate perceptions of MN's swing. For example, some golfers believe that i) he shifted planes, ii) that he swung on the TSP; iii) that he had zero accumulator #3 angle and iv) that he gripped the club in his left palm.
I believe, based on studying all the material at Moe Norman Golf Academy, that all these beliefs are incorrect.
In that thread there is a DTL sequence of photos which implies that MN shifted planes. However, the camera angle is not directly behind MN, and I believe that the "apparent" plane shift is due to camera angle parallax error.
I believe that it shows that his i) left arm is not perfectly in line with his clubshaft at address (not a zero PA#3 angle alignment); ii) that his swingplane is slightly below the TSP; and iii) that he swings on a single plane without any plane shift.
If you are not convinced, watch these videos of his swing (registration, which is free, may be required).
I think that MN's swing very closely resembles an Iron Byron swing.
Ken Martin of the MNGA, also has a discussion of MN's grip and he states that the the heel pad of MN's left hand was above the grip, and that he didn't have a left hand palm grip.