I'm looking for anyone related to Leopold Weismair (birth: 5/9/1882; Ansfelden, Austria). He was married to Josefa and had a son (my father) named Maximilian Weismair (birth: 1928; Vienna, Austria).

not any Weismair in austrian phonebook: http://www.herold.at/en/telefonbuch/

only one hit for Weismair at Vienna-gravesearch, it´s possible Josefa by age, birthdate around 1890:
http://www.friedhoefewien.at/grabsuche_de?submit=true&na...
Vorname/firstname Josefa
Nachname/lastname Weismair
Lebensalter/age 85
Bestattungsdatum/burialdate 17.01.1975
Friedhof/cemetery Baumgarten
Gruppe/group Q
Nummer/number 195
Grabnutzungsrecht bis/right for grave until 30.12.2025
Weiters in diesem Grab bestattet/buried in same grave
Regner Anna age 85
Regner Anton age 80
Waismair Leopold age 58

at last person looks to be misspelling of the name and that this is Josefa´s husband, birthdate was around 1882, which also fits:
Vorname Leopold
Nachname Waismair
Lebensalter 58
Bestattungsdatum 14.10.1940
Friedhof Baumgarten
Gruppe Q
Nummer 195
Grabnutzungsrecht bis 30.12.2025

you can ask at Vienna city-and country-archive for the historical registrydates about the family. maybe it shows details to Maximilian. e-mail-adress at "Zuständige Stelle":
http://www.wien.gv.at/amtshelfer/kultur/archiv/forschung/his...

Thank you!