The stamp unit and the base member further have interengaging means to lock or latch each stamp unit in a position in which the printing surface of said stamp unit is in {HEAD ~ level} with {TAIL ~ the printing surface} of the fixed stamp 
with
The stamp unit and the base member further have interengaging means to lock or latch each stamp unit in a position in which the printing surface of said stamp unit is in { HEAD ~ level } with { TAIL ~ the printing surface } of the fixed stamp
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH