[pmmunro]

Peter,

The varistor confirms that the movement in your meter is a MkIII type. the magnet blocks should be unpainted, whereas the Mk II type would be painted red. (The Mk I type are also unpainted but thicker than the later ones). This however does not mean that the meter started out as a Mk III.

I have an HR Avometer which has a Mk III movement which appears to have been from a factory repair.

Much as we would like everything to be historically consistent, the original users would only have been concerned with having a working meter using available parts. For local repairs, this could have even been without regard for which front panel went with which case.

PMM