BarkeyVA,
Depending on the condition of your drilling, you should be able to use the 2 1/2"low pressure shells.The 9.3X72 was made in different versions and came fron the earlier British 360 drawn case.It is very hard to say precisely when the 9.3X72R was "born", but the earliest German use of the 360 case seems to be about 1878, with the 72mm case length showing up around 1892.
Mike