Why not try it? How much will it cost? Let us know the results. Don't overlook the fact that your seed might be needed to preserve genetic vigor of the heritage varieties. You should contact the preservation organizations. However, I think we were well into hybrid seed 40 years ago.
From a statistics standpoint even a very low germination rate of 2% or 3% could produce thousands of new seeds if it were a worthwhile heritage variety worth saving.