Using IIII rather than IV, the symbols on a 12-hour clock face with roman numerals number:
so a single mould
can be cast four times, with each casting cut twice, in order to make the correct number of numerals:
VIII — I — IX
VI — II — IIX
VII — III — X
V — IIII — IX
The IIX and one of the IXs are turned to form XII and XI.