Perforation Errors - Expert Help Needed

i will attempt to do as the astute posters on the chat suggest. I am not fully convinced of my own analysis and there are some very valid suggestions and approaches put forth here. I always seem to learn so much from chats like this, even though some may find them tedious and even though I have been a stamp collector for +50 years.

I hope to have some more pictures etc tomorrow. Time to go to the hand perforation gauge and put some stamps exactly side by side!