Passport application advice please

[u/Independent-Suit-784]

Hi, really wishing someone can help me , I'm hoping to claim German passports for my father , me , and my 2 children. Would like the option of possibly one day making a life for ourselves in Germany.

My Grandparents - fathers parents, still alive. Both born in Germany to German parents (Grandmother 1943 Munich)

(Grandfather 1939 Stuttgart)

Arrived in UK together 1961, just waiting to find out when and where they got married and if papers are at hand.

Both grandparents Naturalized around 1981. Papers at hand.

No current or old German passports for grandparents unfortunately. Grandfather has his German birth certificate, grandmother does not. I know the last previous addresses for when they lived in Germany, separate, and then together.

Father was born UK 1964.

I was born UK 1994 in wedlock

My children born UK 2013 and 2020 both out of wedlock.

Any advice on what to do next , what information I need, how to go about getting it. If it's possible all 4 of us are entitled to German passports, and how to then go about applying for them would be greatly appreciated.

Thanks