Some more research assistants who worked with Karl Popper have turned up. Given the passage of time there is some uncertainty about the periods of service, for example the logician Lejewski is a possibility from an early period. Other names in the frame are Tyrone Lai, Bernard Burgoyne, Harvey Fields and Ivan Slade. When I have some spare time I will contact all the ex-research officers who I can find to pin down their own dates and any others that they can specify.
This is not a high priority, more important is some correspondence with the journals which published Bartley’s papers to get permission to reprint his major articles in a collection.