You could try tying the clutch lever back to the grip when the bike isn't going to be used for a while, as that would take the spring pressure off the plates and may stop them sticking? I'm not sure I'd want to be hitting the lever with a mallet on a regular basis? Surflex plates are an aftermarket kit and should be available from British bike parts suppliers? From what I've read on other forums, many US T140 owners seem to have a poor opinion of Barnett plates! To quote one owner's opinion (member sboyd) from the BritBike Forum:"I would get new plates anyway for sure as long as you're in there. Recommend MAP or Surflex or even Emgo, anything but Barnett. Lots of low mileage T140's have the original plates and they look great, but they're way too sticky and hard to free-up. If you free it up by jamming it into gear as some have recommended on other threads, sooner or later something real bad will happen."