So, what I am saying is that it is an organic phenomenon that many people do on their own. I know I did.
I looked up Montgomery Ward on Wikipedia, their explanation is as consistent with what you say as with any other theory.
“The brand name of the store became embedded in the popular American consciousness and was often called by the nickname Monkey Ward, both affectionately and derisively.”
I really don’t know that I heard that contraction much around Philadelphia, where there is also a Montgomery County. However, the store itself wasn’t a presence in Philly, the way it apparently had been in Baltimore
“The Baltimore Montgomery Ward Warehouse and Retail Store was added to the National Register of Historic Places in 2000.”