I have a 71 bus with the 'one year only' brake calipers. Just doing the brakes at the mo but one was badly damaged and need to purchase a new calper for 1 side. Not sure which though as i got them mixed up . Have tried the good one on both sides and seems to fit ok? Can anybody tell me if there is a way of telling which side is which? I understand that the indent in the piston has to face a certain way but apart from that they are a symetrical caliper. Can either be used on either side? Any advice greatly appreciated!