Graham,
Thanks, I've finally found it.
Kozice in the province of Viroviticko-Podravska.
I have had an interesting time looking into the Croatian Jewry and can make the following recommendations.
Firstly, read this article by Ed Zwieback:
http://www.jewishgen.org/infofiles/croatia.htmEd refers to Register Offices (Matični Ured) and Regional Acrhives (Državni Arhiv). After a bit of digging I have come up with the following addesses:
For the Slezinger family of Kozice, I would guess that Slatina would be the appropriate municipality.
GRAD SLATINA (= Town Slatina)
Trg Svetog Josipa 10
33520 Slatina
Croatia
AND
DRŽAVNI ARHIV OSIJEK (= Osijek Regional Archives)
Kamila Firingera 1
31000 Osijek
Croatia
For the Kohn family:
MATIČNI URED NOVA GRADIŠKA
Trg Kralja Tomislava 1
35400 Nova Gradiška
Croatia
AND
DRŽAVNI ARHIV SLAVONSKI BROD
A. Cesarca 1
35000 Slavonski Brod
Croatia
Have at lool at these links:
http://www.feefhs.org/links/croatia.htmlI would also contact Ed who seems to be the nearest thing to an expert on Croatian Jewry. He has a new email address which I wil send to you by PM.
Justin