Henny on Family Tree Circles

I am researching an ancestor "FREDERICK WILLIAM ISENHOOD who was born in Frankfort on the Main, Germany in 1834.
He went to Australia approximately 1855 on the ship "Caesar Godefroy" . The German spelling of his name is "EISENHAUER" i think.
He married JOHANNA CATHERINE MARY NEILSON -( born 1850 in Hamburg) I don't have any ships records for her yet, so i don't know when she emigrated to Australia. All i know of Johanna is that she was know as 'MARY' and her father's name was JENS. Johanna is also listed as- JOHANNA C.M., Johanna K.M., MARY J.C. and MARY C.J.
JOHANNA and FREDERICK were married in Wellingrove ( between Inverell and Glen Innes) in 1867. Frederick was 32yrs old and employed as a Railway worker. Their first child ANASTINA C. was born in Inverell in 1868. They then moved on to Armidale where FREDERICK WILLIAM jnr and MARY E. were born in 1870 and 1871. In 1876 they are recorded as settled in Newcastle, where they had another 13 children.
Frederick and Johanna's other children were;
1868 ARNASTINA C. (ERNISTINA?) born in Inverell- - 1882 ALBERT E. born in Newcastle- -
1870 FREDERICK W. jnr born in Armidale - - 1884 LUCY M. born in Newcastle- - 1871 MARY E. born in Armidale- - 1886 AUGUSTUS H. born in Newcastle- - 1873 ANNA LOUISA born in Inverell-- 1888 FLORENCE M. born in Newcastle - - 1874 ELLEN CATHERINE born in Inverell- -1889 EVA.V.A. born in Newcastle - - 1876 JOHN GEORGE born in Newcastle - - 1891 LILLIAN G.L. born in Newcastle- - 1878 ALICE M. born in Newcastle- - 1892 ELSIE M. born in Newcastle- - 1880 ERNEST HENRY born in Newcastle-- 1895 HILDA M. born in Newcastle.
Frederick Snr died 1st April 1909 aged 75 at Merewether and is buried in the Church of England section of Sandgate Cemetery ( Newcastle)
Johanna died in 1926 at Ashfield ( Sydney)

I would love to be able to research Frederick and Johanna's beginnings in Germany- but don't know how to go about it. I understand many records were lost in the war years. I would love any further information on them - or how to research in Germany.

I would love help in researching the "PETER MCANDREW'S" of Aberdeenshire and Perthshire- which is as far as i can get with my MCAndrew family tree research.
1) Peter William Mcandrew born 1896 in Fyvie Aberdeenshire who was Estate Clerk and Head Gardener at Fyvie Castle. His address was "The Cottages, Fyvie Castle" He died of "Gas Poisoning" after WW2
His wife Annie McDonald was a maid ( not at Fyvie Castle). She went on to marry John Hamilton after Peter died
2)Peter McAndrew Born 1866 in Pithochry, Perthshire.He was a Domestic Gardener. In the 1901 Census his wife was listed as "Helen".....but the family say there was never a "Helen" in the MCAndrew family tree.This "Helen" was listed as being born in 1851 in Logie Bachan Aberdeenshire.
I'm hoping someone can give me further details to help keep my research on-going.

I have only just started my research of JOHN LOGAN McINTOSH and HELEN OGSTON CRUICKSHANK who were married in 1915 at St. Nicholas Burgh of Aberdeen. I think Helen and John were born in the late 1800's.
This is all the information i have, other than their son Peter emigrated to New Zealand ( Canterbury) in the 1960's, i think.
I would love any research/information people can offer on this family.