Didn't have too much time but took a crack at the pigeon+whatever other decoded letter :\
I didn't get too far as quite a few of the symbols look similar(used that master cipher) and thus gave me multiple answers. Still not sure on the glyphs that were too faded and I know there are still other similar glyphs not noted in my chart(below) i had to stop and was getting kinda ridiculous for the short time I had on it. I mean look at it
Note: I Color coded the "answers" to their corresponding glyph set...hoo. -_-
Glyph trip
https://imgur.com/gallery/N2o4P
Wip, later