Greg,
If Robin's referral to Vintage Car Parts isn't successful for the Aceca star shaped door striker/latches, possible the following will be helpful: The exterior chrome door handles are interchangeable with Rover P4, so possibly both vehicles may have used the same latches. The AC parts list published in '62 lists the Aceca door latch/locks as 3/4875 (left) and 3/4876 (right). Possibly someone with access to a Rover P4 (at a car show?) can verify interchangability. There are several net venders who do supply bits from Rover breaker vehicles. Incidentally, tried PM you, your email doesn’t work.
Art