Manufacture of Junction Transistors (1961) (thevalvepage.com)

High-quality images of a "decapped" OC45 can be found here[1].

To me these old transistors are just as awe-inspiring as the billions of modern ones you can get on essentially a grain of sand.

[1]: https://www.richis-lab.de/Bipolar88.htm

I want to like that page but (1) the font is awful, and (2) the background makes it really hard to read. On top of that all the talk of Germanium dates the article because Germanium was abandoned as a semiconductor material not long after that article was written.