My collections of Hot Wheels has no end I think I have every model they ever built my dad use to take me to these stores and he would buy two or three of them every weekend and I them all put away still in there boxes apart from many more model cars he bought me just to name some the Ford GTHO Phase III , Holden Monaro's GTS's , Corvettes, Mustang's the list goes on....
If you still have them they may be well worth looking into value. Nice you Dad collected on your behalf.