Jeweler's nut drivers sets. The local eye doctors have always been very helpful with little tools and set recommendations.
Graingers nut driver singles; Westwood is listed for under $2 for 3/32. wiha more than twice that there. Nothing under 4mm for metric.
I've used a dial caliper as a monkey wrench to tighten. Carefully, not on the lever but held the jaws (and lock wheel)