I've viewed a lot of old SA obs from the 1950s. It varies by site, but many would put out 1hrly or 3hrly obs with sustained wind values that were rounded like 34015KT, 33020KT etc. The bigger wind speeds often lacked gust reports as well. I remember seeing a lot of Nov 50 obs that were like 07050KT with no gust speeds. So I've always took those old wind readings with a grain of salt.
weathafella era yore.