Thanks all for the good advice!
Yesterday I made my freewheel remover tool for a four-prong Suntour freewheel. It's kinda crude looking but I think it might work. I haven't actually tried any kind of torque on it yet but a welder at work said he can set me up with a torch and some oil to heat-treat it. Wish me luck. I made it from 12L14 CRS hex stock.
I'm not trying to be a cheapskate or anything like that but I thought it would be fun to try making something simple I could use for bicycle repair. I made a slide hammer out of a piece of scrap brass tubing for installing the lower headset bearing race but that was pretty easy.