I'm not even sure there'd be much to do: just store everything in sixteenths a of a farthing and format on output, much as people do with tenths of a penny toda

I'm not even sure there'd be much to do: just store everything in sixteenths a of a farthing and format on output, much as people do with tenths of a penny today. If anything the numbers are actually slightly more convenient for machines with no divide instruction.