Thank you to all who have responded to my post. This group is so wonderful at sharing information. All of your suggestions and insight have been most helpful.
I may never know for sure which Rabbi my grandfather visited, but I now have a better idea of why he would have made this trip. I only learned recently that the family was Chasidic. My mother had only said her family was Orthodox. However, her mother was a Klepfisz and that family had many members who were Rabbis.
Does anyone know if there were any lists of who were members of specific religious sects? I know so little about my grandfather, I am searching for any means of learning more.