Originally Posted by
Innominate
"Johnnie" was a common nickname for people with the surname Johnson - even Amy Johnson was sometimes called "Johnny".
Yes it was common to use the first syllable of the surname plus "y" or "ie" to make an informal name at a time when first names were not normally used or even generally known. As well as working for Marketing Director "Johnnie" Johnstone, I worked for Technical Director "Tommy" Thomas for some time, but I'm pleased to report that both were happy to call me Allan.
There were also generic nicknames based on surnames, so all Millers were Dusty, Whites were "Chalky" and "Spud" was Murphy.