I worked with type like this back in the day. The burnish type reproduced much cleaner than this stuff. The big problem with the acetate was the edges. Some would reflect light and require quite a bit of touch up once the negatives were made. The other problem was the background was not a pure white so a longer exposure was required which would sometimes mess up the carefully created halftones. When the first laser printers came out they were 300 dpi and not really good enough for serious use in printing but the type in this article were a time consuming pain for anything beyond a headline and photo typesetting was very expensive. We used to have the graphic artist print out at double the size they wanted to use it (or as big as possible) then reduce it down on a process camera as a hack to make the laser printers a viable replacement until the resolution caught up a few years later.
My step grandfather was a letter pressman who had a studio in his home after he retired from the Grabhorn press in San Francisco. His idea of a font was a large box of drawers on wheels packed full of metal type.