Where can I get spares for Sovereign SGT24 grass strimmer?

The spare part I need for my Sovereign SGT24 grass strimmer is the crankshaft ratchet clutch assembly (which is engaged by the pull-start dog to start and free-wheels when the engine is running). Can anyone help? A tiny lug has sheared off one of the two (nylon?) pawls, so a single good pawl, or an incomplete clutch assembly containing a minimum of one good pawl would do. Without this, the pull-start cord jams out when pulled to start because the pawl can flip into its reverse direction.