Hello Phil,
Look into a type of sander that is called inflatable or bladder sanders. We have a few where I work and I use them to shape my baits sometimes. There is an inflatable bladder inside the drum that allows you to use various
kinds of pressure. If you are doing flat work you inflate it all the way, but for rounding you can use just enough pressure to hold the abrasive sleeve on the drum and it works like a charm. I am not sure how much they cost but they are easy to make if you can find the bladder kit.