Oracal, very interesting indeed. P’aps it is a mini ram-solenoid. I will have another look at it. The body is bakelite. It would have enough grunt to flick a switch perhaps. I guess a bakelite body would also cope with high voltage, so anything from radar to ignition related. Mebbe I mistook the ‘brake application’. Kind of a ‘Meteor era’ thing. 

Oracal and Terry P (gold medal), thank you. The counter is free go good home if anyone wants it. 

CD, I hereby apologise to the late A Lumsden Esq and retract my absinthe soaked ejaculation in respect of metric dimensions for bore of Rapier and Dagger. To be sure the Rapier bore shewn below is 90mm-ish but this would obviously fit a smaller piston