I have recently sent a whole history (as I have been able to piece together) of the GRUDGMAN/GRIDGMAN connection to a lady named Irene Bell in New Zealand, although I have not received a response.
GRUDGMAN was the maiden name of a many times great grandmother (off hand I just cannot recall how many greats). It is a VERY unusual surname & seems, in the mid-nineteenth century to have changed the central vowle letter, hence the difference. I can make a connection with New Zealand, but have yet to have it verified.
Please do not hesitate to contact me on my personal email if you would like to know more.