According to an Australian Series 1 expert, who doesn't post on here:
They used theLucas DK4A distributor. But on the earlier versions point adjustment was via a small nut/thread on the contact so it could be moved relative to the arm, rather than the conventional way. The base plate, which is bakelite, is significantly different to the later type as regards the attacment studs and screws for the points and condenser so he should probably look for the later type.
They were quite a ubiquitous distributor, and Lucas was making them (perhaps as spares) into at least the early 1950's.
