The Maxaw 700 is one of my favorite all-time saws. To use modern blades, put the saw in a vice and turn it on. Take a file or small grinder and slowly round off the square edges until a standard blade will fit. Take your time though. Wappat was the first manufacturer to incorporate a retractable...
Green label on the Wappat/Maxaw? What model is that? If you ever want to get rid of it, let me know. I can even give you a few pointers on restoring it.