Be careful when polishing anywhere near the KB logo or the name on the back, the gold lettering will rub away easily.
There is some information on batteries, which you will need to make yourself from either 1.5v cells or 9v batteries, on my website and in the service document, also obtainable from my website..
http://www.kbmuseum.org.uk/kb_images...-1/mp151-1.htm
Mike