Front wiper motor isnt parking correctly when on intermittent, I have to put it on full and then turn it off when it is roughly parked. Is it much of a job to strip these down and fix as I notice you can get a new one from ebay for less than £30.

It's the park switch on the motor that has stopped making contact. Sometimes it's repairable as the grease used goes hard and institutes the switch contacts. Other times the contacts are too burnt to be repaired.

A new motor for £30 seems very cheap, but while you're there, you're better off replacing the rods too, as the ball joints are a know failure point.