Possibly part of an Air Ministry Valve Analogue Computer Racking System from the 1940's.

The Racking System has eight similar units with circuits as below.

Service Valve Equivalents Booklets 1947, 1948 & 1949.

Radio Valve Guide Booklets 1951 to 1963.

C.V. Electronic Valve Registers 1963. (One is updated to 1972 the other to 1974.)