I think this wont help as there are (in case of BO repository sitting on Oracle DB) no foreign keys in BO repo schema. It means that reverse-engineering would reveal table structures, indexes but it would not reveal how BO repository tables should be joined.
I think that the BO repository universes that you can find here or here and here could give you clear picture how BO tables can be joined. And evenmore you can built the reports you need based on these universes.
Marek Chladny 
(BOB member since 2003-11-27)