As I already stated a few times, you likely face a very difficult search. What you have to go for you is the relatively rare name Waltersdorfer, and the possibility that your ancestral family was Jewish and from former Western Hungary.
You may need to get the place names and professions of the two Waltersdorfer (from Zala and Vas county) in the 1890 database, then obtain the Jewish and civil records of these places (via the library network of the Mormons), then establish that these two Waltersdorfers were Jewish (and if not, what religion they were), then work your way backwards, forwards and sideways to place these two and the two Budapest Waltersdorfers into a network of family members and places, and hope that at some point in the exercise, your own ancestors will fall into their places in the puzzle.
You can also hope that someone with Waltersdorfer ancestors may connect to you.
You will likely need to do a lot of the work yourself.