Boy, you are not in an enviable Position!

In your case, Trial and error is going to be one of your best bets as bad as that advice might Sound. Try starting with a late Version of SQL Server 2008R2 and work backwards restoring the database until it is successful. I would not recommend using 2012 at this time because, if my experience is anything to go by, it is not supported by many vendors at all.

There is obviously a great deal more involved than just that (creating the instance, a new database, checking Network Settings and attaching the Client to the database) and if you find yourself struggling too much consider getting professional help.

I will Keep looking at this post just on the off-Chance I can help one step further....