I know this topic has come up in the forums a few times already, but we have made a dial gauge mount for the Taz, for dial gauges that don’t include the back mount.
Details can be found at http://bhivelabs.uk/2016/03/06/levelling-taz-5-3d-printer-bed-with-a-new-dial-gauge/ including the openSCAD code to generate your own model.
Hope this is useful,
Simon