If they are the correct size for your car and they have been stored correctly, and as previously mentioned by Rusty have been kept out of the sunlight, just because they are older doesn't necessarily mean that there's anything wrong with them and they aren't usable.
They are rubber after all and if they haven't been subject to the elements they could be absolutely fine.
The general rule of guarantees by tyre manufacturers is 5 years from the Dept Of Transport (DOT) manufacture date due to the fact that the rubber can start to dry out and perishing or cracking can occur.
If it were me personally, especially with you contemplating having the wheels refurbished and then new tyres fitted anyway, I would thoroughly visually check them over and assess their actual condition, not go off a date on the tyre.
Check for cracking of the sidewalls, obviously the depth of tread remaining, ensure the valve core is tight and then inflate them to the correct tyre pressures and get them on the car to see how they fit and look.
A bit like living in a house you buy and getting a feel for it and then deciding what you want to do to it, before actually doing it ?
