Re: Suggestions, no data
Google has a directory for reunions.
If your fiance's siblings are looking for him too, they might connect.
GenForum has a site for posts like yours:
The people there are amazingly good at what they do. You can get a rough idea of how good they are by the number of queries with replies. Some of the replies are just suggestions; when I looked just now I saw a heading consisting of nothing but a date. No surname, no continent, just a date.
Best of luck!