Validity Of French Overprints And Surcharges

The following images are of French stamps I received as part of a collection.
The C3 appears to be a forgery/fake.
The remaining stamps appear to be forgeries/fakes as well.
I would appreciate any information and/or feedback regarding these stamps and their origins.

Somebody got a rubber stamp kit for their birthday .

Really don't understand why most collectors even buy this stuff .

A few people who buy this stuff are building reference forgey collections to be used to warn others .

There are many things wrong with the French Scott no. 3 ,the bars are too thick and the "O" in the 10 is the wrong font ,it is too thin and not round like the real overprint .

Forgot to say ----Welcome to the board ,seeing this is your first posting .

Welcome to the forum.
You are right to have pulled these out and questioned them.

So do you collect the world, slstiff, or just France? We've had a number of France collectors join recently.

- Jonathan

Thank you for your responses.

This group of stamps was an unexpected inclusion in a purchase; I didn't buy them per se. I enjoyed researching them, but found very little regarding them except the C3, which was an obvious poor forgery. As such, I may offer them as a collection of forgeries.

I primarily enjoy collecting Great Britain, Canada, France and US stamps from the 1800s through the mid 1900s, but everything is fair game.

And thank you for the welcome to this forum.