G'day Anji.
It would be really helpful if you could post a video (with good sound) of turning the motor over by hand (plugs out) then a little quicker with the kickstart then with the motor running. Or even a sound recording with your phone and email that to me.
If you decide to ride her, just do a few short (5-10 mile) runs to see if it gets any worse. Then increase the distance to a few 50 mile rides.
Cheers