On 7/28/11 I wrote a piece about vise handle bumpers.
Since then I’ve changed my method a bit. Now I just use Gorilla tape. I pull off about 8” or so of the two-inch wide tape and rip it down the middle to get two 1” strips. These easily wrap adjacent to the handle end-stop. Over time they compress and make a very effective and durable pinch-preventing bumper.