Exhaust Installation

Hey everyone, tommorow I'm going to be installing a O.E. replacement catback on my '91 P10. I got 3 gaskets with the parts and neglected to ask the parts guy which one goes where. Theres a ring gasket and two flat ones. Would anyone know where these go before I'm jammed under my car? Thanks!

oh yeah, another thing, the bracket on the mid-pipe (b-pipe) looks to be all messed up by a hack muffler shop-job exhaust. Is there a bolt that connects the b-pipe to the bracket? Again, thanks.