I got a very prompt reply to the effect that he's listed 78
obverse dies and 245
reverse dies, including both full and half shekels. This gives an indication of how much extra wear there was on the
reverse die, limiting its life. about 10-15% probably remain to be found, giving round figures of 90
obverse and 300
reverse dies. The number of coins known
per die is very variable, with 2
obverse dies having struck 96% of all the known Year 3 half-shekels, and 4 dies the remaining 4%.
Clearly, a considerable operation was involved, for such a small nation. Large quantities of silver must have been used, and my first impression is that the most plausible source for this would have been the Temple treasury, suggesting that if the Temple didn't actually
mint them, it would have been heavily involved, if only passively.