9.3 x 72R?? That is a very unusual cartridge indeed, although most commonly found in Drillings, as your friend's.
DON'T use the old brass: it is very likely to be weakened by the use of corrosive powder and/or mercuric primers.
If your friend insists on firing this valuable antique, take it to a gunsmith and have it thoroughly inspected and approved.
DON'T try to handload it; the grief of finding data and new brass isn't worth it (remember it is most likely Berdan primed anyway).
If he absolutely, positively has to fire his Drilling, Dynamite/Nobel still makes factory cartridges, $65 for 20, but it is a small price to pay for guaranteed quality ammo, and how much is he going to shoot it, anyway?
The price of brass, dies, etc. simply isn't worth it. This is a big game cartridge, remember, and not useful for most other forms of shooting.
Here is the URL for D/N: http://www.dnrws.com/p676.htm
Walt