[MarkusWandel]

You can watch the whole thing from the very genesis of the turbopump powered liquid fueled rocket. The British did a very thorough documentation project on the German A4 / V2 rocket after WW2 and it's all accessible to the public.

http://www.v2rocket.com/start/chapters/backfire.html

In particular, the pyrotechnic igniter that is mentioned in the article as still in use by the Russians was copied directly from there. Here's a direct link to the spot in the video where it is assembled for use.

https://youtu.be/V_fPdXLx48c?t=2097