First off--great design! I had my doubts with the threaded portions but everything just worked! I printed the gears in gold silk PLA and the fram in black PLA. The face and moon dial are printed in glow in the dark and then hand painted for a bit of character--I really like the way it looks and the fact that it runs is a bonus :)
The weight is a 6lb single piece dumbbell (I cut the rubberized coating off) that I got at a thrift store for $5 (I couldn't find any other weights that would be less than $50 up here in Canuckistan...) I then slid it into a PVC tube--I was leery of a 3d print holding the weight and once its painted gold, should blend in ok
PLA tensile strength is good. It will hold high weights if you make the shell.