First, an intact "CV" (closest to OCK 2275.5, AD 25-50, but with less space between the letters and the border of the enclosing rectangle):
Second, a partial stamp, showing the last two letters of "L.N.P." (OCK 1226.14, 15 BC - AD 5). The inital "L" seems to have been lost in the ridges (i.e., the stamping was poorly done):
Finally, the longest of the three, a "Surisc[us] | L. Non[i]" where the "u" and the "r" of "Surisc" run together in a "VR" ligature (OCK 1282.2, 10 BC+):
