First, what is the diameter of the dial that came with your 1655? Does it fit the case with no 'wiggle-room' at all? You might have some flexibility as 1mm isn't much room.
I have reduced the diameter on dials, and made dials round from flat stock, by using a bamboo shish-ka-bob skewer as an 'axle' in the center hole, and lightly touching it, making the dial spin on the axle, to a bench grinder.
caution: Using metal as an axle will ruin the dial by enlarging the center hole while spinning!
A toothpick isn't strong enough and will break. The bamboo is strong enough. Afterward you can use that bamboo stick to apply lume.
Holding the axle and using my thumbs on each side to steady the dial, I touch the dial edge to the bench grinder slightly. The dial will spin on the axle, and grind a tad, then stop and fit to the case. It usually takes a few times as you don't want to take too much or overheat the paint on the dial. If you have a spare dial you can practice.