My uncles ≈20 year old G-Shock! From what I've found online, it is a DW-002. It's not a G-Line or an Xtreme edition, so I can't find the exact name of it.
Casio G-shock GLX-5600RT-9ER
G-Shock GAB2100C-9A Watch Yellow
CASIO G-SHOCK G-001-9JF Jason series reprint version Yellow Watch "Excellent" | eBay
Casio G-Shock Men's Yellow Watch GA-B2100C-9AER
Casio G-Shock Original GA-110SLC-9AER | Hodinky-365.com