N.B.L - M.A.N. brass diamond plate as affixed to the inside of early Type 4 A1A-A1A Class 41 Warship Locomotives D600 to D604. These locos were built by the North British Locomotive Co who had acquired licences to build Voith transmissions in 1951 and MAN engines in 1945. Not identified but most definitely from one of these locos. Measures 9