Nice to see some other SR rifles.... The 'SR' means Special Rifle. They were produced in batches by Lithgow and put into Storage. You will need to make the damaged/missing parts as there are no spares for these rifles and the loss of the Pistol grip is typical with these rifles up for Army disposal. You will also need to made the sectionlised magazine and bayonet scabbard
There are basically tree factory versions:-
Early, done circa 1960
Late, done post 1969 in a couple of batches
Bi-Centenary, limited to 34 rifles in 1988