I meant in the future, sorry if that wasn't clear.
I already tried the checker pattern on the side and it looked pretty bad.

What do you mean by plan on making a skin set ? In the future or referring to this one ?
For the vector you could maybe do the checker pattern along the side, that would make more sense than the double lines

I do plan on making a skin set very different from what's currently in the game, so I'll try to keep your advice in mind and not mimic any guns I see if possible.

By the time you'd already posted the Industrial set, I was nearly done with the SCAR, S&W, and M4. So I believe that the similarities for the S&W's are just coincidental. I didn't want to leave the one part of the gun that moves (when reloading) the same color as everything else, but I didn't want to make it too dark/transparent either.
The KRISS did take some inspiration from yours, however the fading out at the bolts similarities I didn't even notice until you mentioned it just now. I tried it first without letting it fade out at the bolts and it looked pretty bad. I tried going with a triangle theme (like on the SCAR's magazine) but it looked terrible so my only choice then was white lines or nothing.
The SCAR was also a little bit of a coincidence, but you are right that it would be strange to have 2 of them. I just wrote something on the magazine that I thought would be something at least somewhat related to British authority, so that's what came to mine.

Also the scar has this 'keep calm' message, and it would be really strange if two skins had a 'keep calm' message on it, and both would be a Scar out of all weapons in the game. (Like my sow Scar)

hm. I really don't like how they are so similar to mine. The revolver has the same core design element with a ring on the cylinder at the same place, the vector has the same lines which are erased at the bolts which is a very specific thing I came up with out of infinite possible shemes and the mp7 has basically the same surface mask (although that may just be the optimal way there), if that was made subconcious or concious, it does not exist in a vacuum and id try doing something that is not as strongly similar, especially when they are the main design elements of the skins.