After battling with a 3rd party solution from the Asset Store I thought I would write my own simple little run-time Transform Gizmo for Unity.
You can Rotate about axis, Translate along Axis or Translate across Plane. Still need to figure out the spherical gimbal, but I think I have a good idea how to get that last bit working.
I will share the code soon for anyone that wants it and hopefully the gimbal will work too.