This is a not-as-pretty rebuild of phineasjw's Replicator Bed Level Jig, in Tinkercad. My dial gauge was also too short for the original.
My first attempt to build something using Tinkercad.
The variable dial gauge sets the distance between the top of the extruder tram rods and the build platform surface. Once zeroed it allows the build platform to be leveled at different points on the platform. See these instructions: thingiverse.com/thing:23257
My gauge diameter is 8mm and I inserted four 6mm holes for Eclipse N701-RB magnets. I got these from RS. Also got the gauge from RS.
The wedge underneath should face the front of the Replicator ie away from the drive belt.
My tinkercad file is here: https://tinkercad.com/embed/1WLyThW9irm