hello iv just bought a 8ft knocker box locator off ebay it was listed for spairs or repair it locates to about 4 foot when i got it and it had a homemade plastic wheel on it the lad i got it off said it had, had a new switch fitted i put a new wheel on it but the switch that has been put on it is the wrong one it makes the wheel higher up than it should be. does anybody know of anyone who services them thanks atb