Another update today – first I’ve added a pic of an orange dialled 52-0110 kindly sent to me by Martin (Martback).
Second I found a pic of a rather battered 62-6198 box, which shows that it was known as a ‘Challenge Diver‘. It may be other models from the 1970s were also known as this, echoing the ‘Challenge Timer’ name give to Citizen’s range of chronographs during the same period.
Thirdly, although this is not an update to the page, I have been searching and searching for another blue dialled example of the 52-0110, but with no luck so far. If you spot anything please let me know!