Nalder Bros & Thompson LTD London test set
It looks like you are going to have to find a nice big Variac and isolating transformer to go with that lovely set.
It sure is a nice find and I bet the calibration is going to be good too.
Hi Gents, Nalders were bought out by Reyrolle in the 60's, having been one of Reyrolle's main suppliers of switchboard instruments. Production was transferred to Hepburn in the late 60's from Dalston Lane. It was one of my first projects as a young engineer.