I promised a photo when I installed my skid rollers, so here's a couple.
Changed plans: decided to make double rollers instead of singles to provide greater oil pan protection. I welded them to the bottom of the Scrap Rod's frame where they are barely visible. Cold and rain is keeping me from performing a test drive today ("Where's my global warming, dude?") but I'm hoping they save my poor tortured oil pan from further impacts (two inches clearance from pan to pavement!).
The wheels are 1 1/2": they look kinda like roller skates