Erm. Probably help him correctly set up a software wallet on his phone then send him a certain amount of bitcoin. Not sure why DOGE is an option, knowing that Bitcoin's fees right now isn't even high.
^Of course, if gramps is planning on allocating a decent amount of money to bitcoin/crypto, then probably buy him a Ledger/Trezor.
That's where I planned to send the Doge coins to? He is a trust wallet user and he likes coins like Shiba inu and Doge coin. .
He knows how to handle a crypto wallet already, he is no more a crypto newbie 😆.
I might be wrong, but it seems like your uncle treat those coin as collectibles rather than investment. Anyway, i'd recommend you to buy either physical Dogecoin (which contain some DOGE inside) or hardware wallet which have better security than closed source mobile wallet.