P.S. Other KAMMER records available on MACSE include:
marriage of Adolf and Fani's daughter Ella to Gyula LOVY in Budapest VI in 1909
marriage of Adolf and Fani's son Vilmos to Janka RINTL in Budapest VI in 1915.
death of Adolf KAMMER in 1912, age 61, son of Simon KAMMER and Jozefin BORTSTIEBER; witness Bernat KAMMER
death of Adolf and Fani's daughter Terezia KAMMER in Budapest VIII in 1942. Her husband was Arnold SPITZER. witness was Karoly SCHWARCZ.
death of Adolf and Fani's daughter Gabriella KAMMER in Budapest V in 1945; wife of Gyula LOWY
Vilmos KAMMER's death in Budapest VII in May of 1945; married to Janka KRINBEL (either a corruption or misspelling of RINTL).
death of Beno KAMMER, son of Simon KAMMER and Jozefa BOTSTIBER in Budapest VI in 1920, married to Hedwig CZELLER.
Unfortunately, I couldn't find Zsiga's death. It's possible the records for the year/district haven't been transcribed yet. I'm sure you could find records related to the other branches, so definitely worth joining MACSE!