My cite for the variant pronunciations of Featherstonehaugh was an article that appeared in Life magazine (I think) sometime in the late 1960s or early '70s, called “An Englishman’s Name is His Castle.”
It humourously examined the unexpected pronunciations of British names, many of which are well known (Leicester pronounced Lester, Worcester pronounced Wooster, etc.) Another of the other family name examples it gave was Cholmondley, pronounced Chumley.
The author theorized that if Minnesota were in the U.K., St. Paul and Minneapolis would be known as Simple and Mipples.
The same principle was taken to its illogical conclusion by Monty Python: