When my daughter was very small she salvaged a walnut plaque I'd received at some conference for something or other, and gave it for a birthday, along with a few things she'd made. She said I could make something from it, having observed me make cool stuff from scraps all the time. Sweet.
Fifteen years later I decided my sail finishing bench needed a proper seam rubber, so I scribbled up a plan (above), sawed a section out of the plaque, attacked with a number of power sanders and finally some 400 grit paper, creating a simple, traditional tool that's quite comfortable in the hand. It's a little smaller than customary, but I'm only doing repairs and after a few years of use it still feels just right.
Better than watching re-runs.
Can you even buy such a thing? I'm not sure. You can buy one of these for rolling seams when gluing or welding roofing seams, but the sailmakers I've watched all have the home made sort.