Are you up North in Tasmania or down South?? I know that it is only about 2 hours in the difference but if it was up North ( Deloraine) , call in and see one of the best gunsmiths in Australia ( Alex Beer )and although now retired from gunsmithing is a wealth of information so you might get some advice straight from the best IMO.

Would suggest that you make sure that he is home 0400 474 507