This is a fine set of instructions with many notable features:
I have been told that it dates from 1958 - but I suspect that it could date from any date from then until the early 1960s. It has no dates on it.
The ‘SunTour Eight’ product name is one that I have not come across before.
The instructions suggest that the rear hub should have 125mm Over Locknut Dimensions - which is very sensible but possibly quite progressive for the late 1950s. The unit hub design is also quite sensible and advanced.
Amongst some particularly fine weird english, the statement ‘Nowadays the derailleur gears are most popular and universally used among the cyclists in such European countries most advanced in the bicycle industry, as England, France and others.’ Is notable for the way it shows Japan deferring to Europe in bicycle technology - not something that we would instinctively expect today.
I love the random graphic elements added to spice up the text. The image at the bottom of the back page is particularly splendid.