I have just cleaned up mine (it was on another ST11 for 8 years or more) and it works as good as new. May just need a clean up and a proper clean of the solenoid in vacuum canister (easy to do, and it just cleans away gum build up that makes the vacuum operation sticky). I have the instructions for this as well as installation and trouble shooting instructions. I found McCruise quite willing to help by sending through specific model instructions, so if you get stuck should not be an issue. The type of activation switch and computer are the main identifications needed.
Also, ask if it comes with the 6 rare earth magnets (in the heads of the bolts holding on the rear rotor) that are needed to get a sensor reading off the rear wheel. They should be able to be bought if needed, and I have some to measure up.
