In those days when we used to discuss technology, he mined Bitcoin (BTC) in an old pool. He referred to his mining rig as the "7970." However, since the value of Bitcoin wasn't very high at the time, he just left it in an old wallet.
A few days ago, he called my mom, saying he needed to speak to me. I later got in touch with him, and he asked me how to import his BTC private key. He said, "Do you remember that I mined Bitcoin with the 7970?" I replied yes, and he mentioned he didn't know how to import the key.
It can be this graphic card.
https://www.techpowerup.com/gpu-specs/radeon-hd-7970.c296The time of its launch is quite fit with your uncle's early mining activity.
The Radeon HD 7970 was a high-end graphics card by AMD, launched on December 22nd, 2011
If he can mine bitcoin, I think he is technical enough to search on how to import Bitcoin private key, and do it by himself.
He can try with this guide.
Importing your private keys into Electrum.Depends on script types, he has to use either one of three formats.
p2pkh:privatekey for address starts with 1
p2wpkh-p2sh:privatekey for address starts with 3
p2wpkh:privatekey for address starts with bc1