I dont think that I explained my issues properly, The starter motor was replaced with a ND after the damage was caused to the Ring gear. By both the 9 tooth starter and the starter sticking on.
Currently it works OK most of the time, but on occasions baulks and does not engage properly. The engine has 9.5 CR pistons and requires quite a bit of effort to turn over even with powerfull starter and battery.
Options might be:
1 Clean up Ring gear with dremel, take off the nicks and burrs.
2 Find new ring gear and fit, rebalance flywheel.
3 Replace flywheel, get it lightened and rebalance
The problem with all the options except 1 is that the engine was balanced together with flywheel and clutch and I don't want to go down the rebalancing route due to time and cost!