Reddit mentions of I Read Past My Bedtime - 3" Sew/Iron On Patch Humor Joke Reading Book Worm

Some of these are probably the same ones you found (don't know for sure since you didn't include links to the ones you already saw), but I found several that would be cool to encourage a kid to read.

There's this one that says "I Love Books"

Then this one that says the same thing but it's a different design

This one that's just a book that says "Reading" on it

Another form of "I Love Books"

A patch that has the ABC's on a book

Yet another form of "I Love Books", but this one has a really cute bookworm on it

A cute bee that is encouraging kids to "Be A Reader"

A funny one that encourages kids to stay up past their bedtime to read books

One that just has a picture and the word bookworm

One that's literally just books and an apple

Yet ANOTHER form of I Love Books they seriously seem to be everywhere

This one asks people to "Tell Me A Story"

This one is for a kid who Loves Story Time

This one says that the kid would Rather Be Reading

And, finally, a couple of the Seven Dwarves reading what is apparently a book of fairy tales.

I can probably find more suggestions, but these are the ones I already had bookmarked (I give them out to kids at church to encourage them to read more). If you need me to find others, just let me know!

Edit: forgot to mention that you can attach them to a backpack, belt bag, maybe a canvas bag, or his favourite jacket or pants or something. You can also ask him where he wants to put it. Kids are really good about choosing where they want to display something, and I can guarantee that he'll choose something he's proud to show it off on.

I believe this would be an adorable first badge for your son <3

If he continues his journey into reading, I feel like this would be a great patch after he reads 10 or maybe 25 books!