Did not take notice of this before, but on Harold A. Skaarup webpage, the wording infers the nick name was thought up as a result of surviving the war?
http://silverhawkauthor.com/tanks-an...useum_973.html
The notion of this particular Sherman being a unique survivor may have already been on the minds of it's crew at the close of August 1944, as described in this pdf article:
https://scholars.wlu.ca/cgi/viewcont...00&context=cmh
regards,
Jack