P-07ShortLee, one of the other chief differences in the SMLE I and SMLE III forestock is the inletting of the rear sight protector on the III/III* pattern.

On another note, I do not believe it is possible to alter a post 1921 forestock to the earlier III volley sight pattern due to the altered configuration of the lower stock immediately behind the middle band/outer band. So that effectively negates the possibility of altering a later stock to the earlier pattern. You might get lucky and locate an early Aussie III/III* Queenland forestock and it MAY be possible to alter it for the volley sight but hope you have access to the rest of the wood furniture as it's scarce.

Best solution would be to purchase a new made forestock or locate an original volley sight forestock from that era. They turn up with some regularity on eBay if you watch close. One thing's certain--it will be an expensive undetaking.