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 level with {HEAD ~ the printing surface} of {TAIL ~ the fixed stamp} 
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 level with { HEAD ~ the printing surface } of { TAIL ~ 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 OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL