Ossowski: Dirschau/Tczew (Rukoczin/Rukosin)

Hello from Australia,
I am writing a book on a family that immigrated to New Zealand in 1875. I have tried desperately (for about a year now) to find online records of this family, and to date I have only found two records that have come from someone called Herta on ow-preussen:

345/297 Rukoczin

Johannes 8. Febr. 1869

[Parents] Martin OSSOWSKI and Anna RICHERThttp://list.genealogy.net/mm/archiv/ow-preussen-l/2007-04/msg00199.html

42o/327 Rukoczyn

Franz Vinzent 3. Apr. 1872

[Parents] Martin OSSOWSKI and Marianna RICHERT

[God Parents] Franz GÖRSKI and Barbara SARNOWSKAhttp://list.genealogy.net/mm/archiv/ow-preussen-l/2007-04/2007-04f.html
I am hoping that someone is able to assist me to find out some more information about this family. I would like to know if the family came from the Tczew region, or if they only lived there temporarily. It would also be interesting to find any other records for the family (such as a marriage record, and the records for the other children). Some details that may help:
Parents:Martin Ossowski (or Marcin) b. 1837 - 1839 Anna Richert (or Rychert) b. 1837 - 1839 and m. 1859-1861
Children:F Berta Ossowski b. 1863F Juliana Johanna Ossowski b. 1864F Rosalie Ossowski b. 1866M Johann Ossowski b. 1868*M Franz Ossowski b. 1870*
*record above
I am assuming that the family has lived in the Tczew area for generations, but it would be good to find out if this is true.
Thank you to anyone who is able to assist me. If I do not receive any replies, I may to find a professional genealogist to assist me - if so, can you recommend any local genealogists that may be able to help?
Many thanks,
Hayden,Sydney