Well Framtons are part of Jepson and they do say on their website that
Ace Digits are exclusive to Framptons. The cast aluminium polished digits give an expensive feel to any restoration. Most suited to vehicles registered before 1963
Although on the Jepson page, it says the ACE raised aluminium letting plates are :
ACE Cast Aluminium
Rare cast aluminium peaked digits in the ACE style, polished to a high sheen finish.
Suitable for vehicles:
Between 1903 - 1920: Car 3.1/2" digits
You'd think they'd get their story straight wouldn't you.....