How does this work? Well, someone digs it up and makes an initial catalog, but because they contiunue digging, no analysis. Then that person dies. Someone hasoto pick up and know or have a suspicion what is there. If not, it sits for years. The reason Dan finds the stuff is because it has sat in libraries for years. The few people who know Coptic well enough to do this is another problem. When the location is obscure and circumstances unusual (these mss were in the southern most part of Egypt and were rescued as part of a rush operation before the Aswan dam flooded out the area), not many even know something might be happening until something surfaces.  There also are government agencies to deal with, since these are their antiquities. So it is all very complicated.