My dad used to make his own hand spears In souther California in about 1939. He used a long wooden pole, and had a blacksmith fashion a single barbed harpoon type point. He said he attached it using a brass sleeve that he would heat, to expand, then slip over the end of the pole, and douse the sleeve in water to shrink it.
When I got into spearfishing in about 1996, he was impressed by the Alexander slip-tip design, and said that the barbed harpoon tip he used could never hold a white sea bass.