Roger,
I've heard lots of solutions for replacements including old phonograph needles, trips to the machine shop, etc. Small finishing nails are probably the easiest. Cut the nail down and shape the point. You can temper it with your propane torch if you want to, nails are pretty soft metal. Heat it up cherry red and quench in water. Heat it up again and let it cool gradually in air. That will make it fairly tough, hard and durable, plenty good enough for a marking guage. I can't imagine wearing a point out on wood anyway?
My Best
Randy
