[pmmunro]

Ramjet,

It looks like what you have is a High Resistance Avometer - much rarer than a Model 7 and a type which could be considered the forerunner to the Model 8. (There are in fact two versions of the HR Avometer).

This fits with the serial number and the date of manufacture implicit in the serial number.

For more details, see a previous thread on Avometer identification.

Peter M. Munro