Cropico Type RBB5 Resistance box 0 to 111Ω 0.5% on three highest ranges and 1% and 2% on the two lowest. Resistors are manganin wirewound. Made by Croydon precision Instrument Company. The firm which was founded in 1952 is now part of the Seaward group of companies. The RBB range of decade resistors are still manufactured today. Croydon UK date unknown.
Lektrokit was a trade name of A P T Electronic Industries Ltd of Chertsey Road, BYFLEET, Surrey. Originally, in the 1950's, the firm was known as All Power Transformers Ltd. By 1978 the firm then known as Electerminations Limited was in liquidation.
