This 5 cc glow-plug motor was passed along by my good mate Peter Valicek. It has been in the collection of a German friend of his for over 35 years, but has never been identified. It was apparently sold as a MOKI M-1 on the basis that the right-hand side of the case bears the M-1 designation. However, the left-hand side of the case bears the stylized designation CS/R 5, which is inconsistent with any known MOKI designation. Moreover, this is a 5 cc engine, whereas the MOKI M-1 was a 6 cc unit.

The engine is clearly an example of a series production effort - it uses die-casting throughout and also bears the serial number 198 on the left-hand mounting lug.  Question is - who made it, where and when??  Can any reader help??