[The Philpott]

Okay, so K operates correctly but resistance ranges kaput..The windings for 1 kohm and 10kohm ranges are on the little board.. As you'd expect, their resistances should correspond to APPROX half scale on the respective ranges. It is quite common for one or more of them to have become cooked, or just become o/c through age,corrosion,embrittlement at the ends of the wire..all the usual gremlins.

The leaf switch stacks are quite often worn or abused and this can cause resistance ranges to fail.....in addition note that there is an extra leaf contact that closes when the 1 kohm range is selected.

As regards the little bobbin, it does not appear in either of my donor meters (and there's no hole to suggest one was ever there) so it's possible it's a factory tack-on repair from the 'fifties or a little later- a lot of them went back for repair after 10yrs service it appears-perhaps as a routine refurb. or when some were retired from the ministry (speculation)

It looks from the image that your bobbin has replaced the 150v board winding, but note that it only drops around 75v in itself...i'll get an exact value later if it's not on the schematic already provided earlier in the thread! There is certainly a winding missing from the end of the board, which supports this theory.

Dave