Looking for Laue family in Calvörde middle 1800s

  • I am researching the family history of the Laue family for my friend.
    We live in South Africa
    His family emigrated to Natal South Africa in 1890.
    They were 2 brothers who originated from Calvörde.
    1. Wilhelm Friedrich Christoph Laue * 29/03/1858 married Hanna Friederike Louise Scherf * 13/11/1859
    Wilhelm was the local shoemaker in Hermannsburg Natal South Africa.
    They had 4 children already when they emigrated:
    Wilhelm * 07/05/1880, Hermann * 25/08/1881, Otto * 11/08/1885, Marie * 18/02/1888
    2. Friedrich Hermann (Fritz) Laue * 13/11/1859 - was single when they emigrated.
    The family arrived in South Africa 19/06/1890 on the Dunbar Castle, which was a shipping line operating between England and Australia, stopping over obviously in South Africa. This means that the family must have first gone to England and then on to South Africa. There are no records of them in the Hamburg Emigration lists. Bremen lists are obviously non-existent. I have written to the St-Georg Kirche in Calvörde, but have received no replies - I guess they are understandably too busy. I understand that gravesites are rented for 25 year periods and so trying to look in cemeteries in Calvörde would prove futile.
    However, I'm hoping that the 2 brothers left behind some family when they left.
    Although they were part of the Lutheran Church linked to the Hermannsburg Mission in Natal, they were not missionaries. They appeared to be farmers and tradesmen.

    Can anyone recognise the above names or offer some hints and clues please? The difficulty is the changes in politics and districts/regions over that period.

    Many thanks