Very small part holder, indeed. I used my fly tying vice, today. The gap is extremely small- 1/32" but for parts that small it worked. Careful be, mine has a cam lock and it would be easy to crush a part. Mine does adjust so you can just about feather grip it. More expensive ones even rotate. One could put a part in one and set up a brush in a third hand, load the brush and rotate the vice.
If I had one like that I’d try that for perfect circumference lines.
