He had a bunch of wire-wrap-like boards made, but soldered the IC's to pads, and then wired everything together with WWW, but he did strip the ends.
Indeed, with "normal" WW, like the one made in western countries, it was very hard, if not impossible, to make reliable solder joints without stripping. That matte white WW seen in the pic was what we use to have "on the other side" of the Berlin Wall. Not sure where was made that white WW, but I assume somewhere in Eastern Europe, or maybe USSR.
It might have been made in RSR (Socialist Republic of Romania) as well. At that time, any import from western countries was severely limited by the PCR (Romanian Communist Party) if not completely banned, so western WW was like Unobtainium here. To counterbalance the lack of western parts and/or technologies, the Eastern block countries were reinventing the wheel all the time, or simply copy by reverse engineering or industrial espionage. In the particular case of my country, Romania, there was a famous case of a security officer, General Pacepa (the head of Romanian intelligence service), who flee the country during the communist regime. Later, he wrote a book "Red Horizons"
https://www.cia.gov/library/readingroom/docs/CIA-RDP90M00005R001300010017-4.pdfhttps://books.google.ro/books/about/Red_Horizons.html?id=zQ7LSucBylAC&redir_esc=y&hl=enwhere he described the industrial espionage, including some interesting story about stealing Texas Instruments technology (I think it was about the military 74xx TTL family circuits, but not sure), the plans of a western tank, incredible details about the life of Ceausescu family and other top political figures under the Iron Curtain.
Anyway, back to our eastern European WW, the insulation was very bad when compared to the "normal" western WW. As soon as that matte white insulation was touched with the soldering iron, the insulation burned itself into smoke, yet the solder somehow manage to wet very well the "carbonized" wire, so I used the crappy quality of the insulation as an advantage, in order to avoid stripping and cutting. It was even possible to put a blob of solder in the middle of an unstripped and uncutted wire, which was very handy, especially for memory busses.