Each of the four sections of the Mosquito Jig introduces a new right hand pattern. That is the essence of the exercise in my opinion. We should all ignore the handwritten markings. It's true that  A minor and E chord shapes are used but this is a rare instance of the hand markings being correct. The four sections have been marked by hand as follows: the first as A, the second as nothing, the third as D (at least I think that's what it says) and the fourth as C.  Whether this is indicative of personal meanings that are the equivalent of a secret code, or the result of a mind that was not the sharpest knife in the drawer, or simply the work of an intelligent person who was new to music notation and got confused is beside the point.  Most of it misleading and wrong and should be ignored.

I am actually removing the markings on my copy -- through the magic of Photoshop -- and perhaps, in the end, with permission, I will be able to share a cleaned-up copy. I notice, for example, that frets have been filed in sometimes and I think that's a hinderance to learning to read ...

A cleaned up copy would be fabulous.  I hope this is not asking too much, but what do you think about posting a cleaned up copy each week of the pages to be worked on in the coming week?

I think posting the cleaned-up pages is a good idea. I don't think there should be a problem because I believe the book is early enough to be in the public domain, but I want to check with Joel first since he's the one who gave us access.

It is in the Public Domain, no problem with that. I think the C notation is a 17gen Xerox of a 50's mimeograph...

Might be easier in photo-shop to use the A notation and do the old 'add a staff line underneath, delete the top one, drop 3 sharps...'

Or, it can be very easily keyed into something like Musescore. I can't promise to clean them all up. Adding the 1-2-3-4 counts below the staff was harder than it looks. The notation part is as easy as typing g,e,c,d,c,c,g,e,c,d...

Thanks for the link to the cleaned-up version of the tune. I'll add it to the original post so that it's easy to find!