Wondering Worth Or Information On 1920 Stamps And Envelopes With Letters

I have a couple really cool envelopes and letters with some old stamps. Was wondering if and what a value may be on them. Of course google tells me I will be rich but we all know how the internet is :)
My grandmother was a postmaster her entire life so I have inherited quite a bit of neat things when she passed away 20 years ago. I was browsing through my storage and seen these and thought they may be worth something. Can anyone tell me a round about value? Hopefully I'll be able post the pics or this post will sound silly :)

Thanks in advance
Michelle

Fun hobby.

USS Pelican
https://en.wikipedia.org/wiki/USS_Pelican_(AM-27)

I am really new but I have a collection of cut squares that I recently researched. I doubt there is much $ value here, judging by condition alone. Could you answer four questions about the top envelope?

1. Dimensions in centimeters?
2. In The word Postage below the T, is that a red line crossing the inner circle or something else, perhaps part of the cancel ink?
3. What is the white mark on the circle of the two on the right? Missing ink from the die or a scrape or scratch that removed the red that should be there?
4. Hold the envelope open and shine a light into it and look for watermarks visible by looking on the outside of the envelope where the light shines through, Are there any and if so, what do you see?

I believe this to be design #U93 on white paper so your objective should be to identify from what die.

I collect war time and military related covers and letters that have something to do with what was happening on or near particular dates and locations of interest. I also collect letters that reveal a soldiers opinions on or observations about military operations. Does your letter express such things?