Major, Mayor, Meyer

My grandfather was born in Czech in 1889-1890 and when he finished school he went on to learn to be a piano tuner.
Is there any way of finding out where he would have learnt this trade? He lived near Plzen (Svaty Kriz). I have been searching for many years to find out anything at all about him with no success. Can anyone help me? I live in Australia so it is hard for me to find anything.
On his marriage certificate in 1922 (in Australia) it states his name was John Major aged 32yrs.
Before coming to Australia, he lived in Chicago for about 5 years and was said to be working as a piano tuner for large piano companies.
On his marriage certificate it says that his mother was Josephina Otis and His Father was Josef Major. I found a picture that says “my brother Vaclav, a U.S Citizen”, and another photo of a man, his wife and child, on the back it says “my brother, wife and child. 77 Borek Rokycan Czechoslovakia Europe” so he had a brother.
No one has ever been able to find any trace of John Major (if that is his real name), no birth records, no travel or immigration records, no relatives, no record of his parents or brother.
The first record of my grandfather is his marriage certificate…….John and his wife Elise Holik (from Prelouce, East Bohemia) had 3 sons and one daughter.
Elise was 16 years old when she married and died in childbirth when she was only 22 years old,
Their only remaining child is their daughter, my Aunty Rita who is now 90 years old and she would dearly love to know if her father had any relatives or descendants as he never talked about his past..he was always a mystery!
Regards June Austen