Hello all from California! I have been a coin collector for a few years, and am known under this same username in the coin community forum. My father passed away about a year ago, and he was an extremely avid stamp collector. He specialized in Ryukyu Islands which makes up the majority of his collection...but he also has a fairly extensive US collection. I have been selling Ryukyus on
ebay for a while now, and am just starting to delve into the US material, as I realize there is some value here.
US looks challenging to me, because of all the subtle differences between stamps that have huge value changes. He has a complete set of mint airmails, many of the early used stamps, many mint commemoratives....and he also has some serious collections of some of the "back of the book" material. I will want to focus on some of the "Newspaper and Periodical" stuff, and try to figure out what some of these are worth. It looks like a lot of them have a high cat value(though I realize in this market, 30-50% of cat is more realistic). Some of them have the scott number written on back(which helps me a lot)....does this hurt the value? Here are a couple of his collection. Is anyone familiar with how to determine which series these are in(other than the obvious number in the back in this case)? I see "hard" vs. "soft paper in Scott, but I am still having a hard time...and some of them catalogue over $1k


He also has a used #39, which by reading previous posts, I am learning that the cancels may be counterfeitted on mint stamps. I assume my dad knew what he was doing, but I will probably send it in to be sure. How would it grade? Here is a scan of it


Here is a scan of a few of our early material.


Anyways, my goal will be to sell most of it for my mom, but she said I can keep stuff I am interested in collecting(I have yet to determine what that is). I think I like the commemoratives and airmails, they are easy.

I am hoping I can seek advice from you guys regarding this material, as I have a lot more material I will need to ask about. I know Ryukyu, but US is a whole different animal....much more complicated.