hey Jacknono,
is ur Fender strat American, Mexican, or Japanese? they have got different allen key sizes. the Am and Mex uses the same keys, but its difficult to find them in shops here as they are of not metric sizes, its in inches. try to get them from authorised fender dealers, ie swee lee or GG. but davis might be able to bring the original as i saw them having original fender parts. or GC. the Jap is easy to find as it is in metric. most hardware stores carry metric sized hex keys.
beware that if u uses the wrong allen key, it might strip/damage the hex hole, and it is costly to replace/repair them.