A few small changes to the excellent original design by cmh (https://www.thingiverse.com/thing:3220573)
Handle is one piece and spoke seat is removeable. Designed for larger spring that goes around the existing indicator's plunger cover so that no spring seat needs to be printed. Clamp is redundant since the dial indicator now screws onto the backside of the base.
Requires four M2 x 6 mm flat head screws (which can be eliminated if you use the clamp instead), six M2 x 12 mm socket head cap screws (only two if you omit the clamp, a cheap Chinese Digital 12.7 mm Dial Indicator, and one spring 1 mm x 12 mm x 50 mm.
You will need to sand the knurled portion of the plunger cover for smoother operation of the spring. My method was to chuck it in a power drill and then run it along a sanding block with 240 grit emery cloth. You don't need to make it completely smooth, just knock off all the points on the knurled end.