To give a sense of the further breadth of my research, as well as of my conversations with the author, here is a list of the links and images sent to me by Anja during our many hours on Skype over the course of several months. This is only the research that took place after my initial draft i.e. after I had done countless hours of research on my own, so it is only a tiny portion of the whole but it gives a sense of the topics covered and, perhaps, of the unpredictability of the kinds of questions that will arise when doing this kind of work.
https://nahtzugabe.blogspot.com/2013/02/ufo-angriff-4-zwischenstand-die.html
https://www.youtube.com/watch?v=Lcn08b4ITTw
http://www.cranzwestend.de/rossitten.html
https://www.youtube.com/watch?v=sq95TS-Ak6Q
https://www.google.com/search?client=safari&rls=en&q=thunder+horse+oil+rig&ie=UTF-8&oe=UTF-8
http://www.amandamustard.com/pigeon
http://www.strassertauben.de/informationen/musterbeschreibung/rtfgeh.htm
https://www.featherbase.info/uk/home
https://www.pinterest.de/pin/85075880445215116/?d=t&mt=login
https://www.jacques.de/wein/8/rose-sekt-und-mehr/bag-in-box/
https://de.wikipedia.org/wiki/Konstatieruhr
https://www.grandoceanmarine.com/marine-safety-equipments/personnel-transfer-basket/
https://www.halden.ruhr/halde-haniel.html
https://de.wikipedia.org/wiki/Erschlie%C3%9Fung_(Geb%C3%A4ude)
https://www.ruhr-tourismus.de/de/reisen/ungewoehnlich-uebernachten/ferienwohnung-vierspaenner.html