Haven't found any grips yet. As a temporary thing I bought a length of that foam insulation for copper pipes from Bunnings. Some short lengths of that will get me out of trouble for a while. I'm not working Thursday so I was thinking I might try to run up the engine then. I'll let you know how I go with the rollers. They will have a 12mm hole for the axle and I'll leave them bare timber so you can finish them however you like.