After thinking I got a bonus with the reverse switch on me new 2nd hand gear box I've busted it 
I cleaned the box out with the karcher and turnd it upside down to drain. Later I carried it back into the garage upside down and when I placed it on the floor I rolled it over to right side up and heard "crunch" - the plastic cap on the switch had copped it and bits went everywhere.
You win some - you loose some