Genuine ancient and mediaeval coin dies are very, very scarce, since unlike the coins that were made from them, the dies were never intended for public distribution. Like most other ancient crafts, die manufacture and use was a "guild secret" within the mint, one which the mint workers would have been expected to guard with their lives; dies were never just casually thrown away, just in case the unscrupulous found them and started making his own coins.
Finding a single die is rare enough. Finding a matched pair is even rarer.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis