When I look closely that work actually looks fine. Solder flow is reasonable and I don't see cold joints. The only true WTF was where a resistor had been ripped out for whatever reason. Also it's unclear whether they had flux-core solder yet and they are essentially soldering in 3D. (Former electronics assembler here.)
I did a bit of cursory research and it would appear that flux core solder was invented in around the mid-20th century, so there's a very good chance that they weren't using flux cored solder.
According to Kester, the solder company, they were formed in 1899 to make flux cored solder. Looking at the 1933 Allied Radio clearly shows Kester rosin core solder.
Rosin core predates that computer by a half century, at least. Kester was formed in 1899 just for that purpose, according to them. Was just looking at Allied Radio 1933 and rosin core solder is prominent. Not sure why the comments; radio building was at high form in the early 20th century.
Thanks for that pointer, all I could find was a vague wikipedia article. Obviously soldering was well established. The specifics of what was available weren't clear.
