US #1468 Gum Error Found?

I have 3 mint stamps with mottled gum on the back. Originally I supposed that these were storage issues or partially used, but uncancelled, etc. However, I was going through a large batch of mint stamps, and found 3 of them with these "splashes" and one with full mint.

a) Is anyone else aware of it?
b) Are there people who would be interested in these stamps? I know people will collecting tagging variations, but wasn't sure about gum errors. I'm willing to share free, but would love to know why, too.

Thanks for any feedback!

P.S. It's hard to photograph it to show the gum difference, though I will if needed.

Welcome.
Please note that for safety reasons buying/selling/trading/swapping is prohibited until you have 50+ posts.

In terms of your gum question, a few images would greatly help. Obviously taking photos of gum is hard but you could try holding the stamp at different angles.
Don

Thanks! I'll work on the pictures today.

I'm still trying to get used to this interface, too. Should I edit the post to include them, or can I just reply to the post?

I added that because I thought that maybe people weren't answering because they thought that it was a sales effort. It's more of a should I just throw it away like I do torn stamps while I'm cleaning up my collection. I put my used ones in a rubbermaid box, and my mint stamps in Verio sheets or mounts if they have a value over $10.

Understood.
You can simply 'add a reply' to post your new images. If you have any issue please let me know and I can help.
Don