I don't think my newly acquired AVO Model 8 knows what it is!
The serial number is: 52918-C-1056 and there is a space between 250V and 1000V on the D.C. Range switch ( no 500V setting ) which suggests a Mk II but then there is a fuse ( and a spare ) in the battery compartment and the Working Instructions on the back says "Model 8 Mk III"
Either way, it don't work - not yet anyway
Best Wishes to all, Lee.