"Third Hand" Magnifier replacement

I buyed my "third hand" without a magnifier ... very cheep.
The Magnifer i used was part of a Screwdriver set but the outer ring brakes a while ago. So Magnifier glass, incomplete "third hand" and 3D Printer ... what to do? :D

Messure it, Scad it - slightly testing its size ;) - slice it and print it.

Additional parts:
"third hand"
Magnifier glass(50mm, 5.5 - 2.4 Convex)
1 x M3 hexagon full nut (DIN 934)
1 x M3 (cheese head) Screw