Leave it alone and forget it.. It's a nomenclature Call it Cent or Penny and everyone understands what it is.
The other night I was watching MeTV and saw that CarSheild added one to that list: Car breaking down.
Only the new 10 and 5 pences circulated before 1971, (from 1969) and even then they had the value of two and one shilling respectively, and possibly, from memory, likewise the 50p at a value of ten shillings. After 15 Feb 1971 the old money still circulated for a few months, but at revised decimal values. Two good books about all this were published by Spink last year.