A note to all taking upon this challenge: there are actually many alterations. All but one are extremely subtle. mudhut1000 has done a masterful job of creating them. As his rules state, any noted alterations are worthy of being "put in the hat" that will be drawn from.
I'm going to state another hint that hopefully won't ruin his challenge: comparing the stamps directly to the side of each one is useful. mudhut1000, if I have revealed too much, let me know and I'll delete this reply.
This forum doesn't have a useful system to send images to another user, so you will need to utilize a 3rd party image host. Imgur . com,
https://imageshack.com/, facebook,
www.imagebam.com/, imgbox.com, photobucket.com .
Any can be used. Don't post the link to your image here. Click on mudhut1000's name, then select "Send an E-Mail". Copy and paste the website address so he can view it. Don't forget to include a description of how you found the alteration. As his challenge states, "who also best describes the alterations. They win the Grand Prize!" Describe the alterations based on how you found them, details of how they are apparent, and try to use images/arrows/etc. to point out the differences.
Again, good luck!