Hi RobertS
Unfortunately these infos are EXTREMELY hard to find,I can only advise some contacts
http://rally.avtomanija.com/
This is the website of a Slovenian car-magazine which was extremely popular in Yugoslavia and dedicated a lot of pages to Yugoslavian motorsport.
They still run,if anyone has some infos they must be the ones...
The following sites hardly have these infos,but if you are desperate....
I can put your requests to www.desno4.com (register) ,the biggest Croatian forum but I doubt you will find any infos there
http://www.autoklub.hr/ is a old Croatian newspapaer who used to follow our motorsport (now very little pages)
http://www.automototrend.com.hr/ a magazine which followed rallying a lot but then it stopped publishing,now its a website
www.pungas.com great forum,but little activity lately