Great article! Really awesome of you to take the time and ELI5 the whole concept to a 10 year old, I am sure it will leave an affect on him about value and he will remember it growing up.
I have lately started giving out these coins as presents to friends and relatives:

They are goldplated coins from the website: www.denarium.com, which I found on the website bittiraha.fi which is one of the few Finnish websites that assists with buying and selling bitcoin.

I purchased some in a bulk, put in some bitcoin in them and gave them out as gifts telling the persons that it sort of has a double value to it and most of them understood the gesture and appreciated the gift, even though they didn't know much about bitcoin.

For those that don't know this is an image from their website:

The coin has a hologram in the back with a visible public address to your wallet and if you want to access those funds at any time you just remove it and read the backside.

Anyway, in case you need a cool gift idea, I'm sure you can find more of these bitcoin coins locally. Wish there was a place to order them with other coins wallets, maybe even Steemit accounts? ;)