New owner, trying to identify missing parts

[Tight_Bolt_Hole]

So, I picked up a banshee at storage auction. It's missing random bits and pieces. 

I'm trying to figure out the best thing to do with the exhaust. I have the expansion chamber, mid pipe and silencer/spark arrester(hope that's the correct part names).

 however, I'm missing the connecting hardware between the three. I found the clamps that go between the Expansion chamber and mid pipe. 

What goes between the mid pipe and silencer? Someone tried to weld the two pieces together, as shown in the photo below(I knocked all the shit weld off and cleaned it up with a Dremel tool).

Can I simply squirt some RTV high temp between the two and use the correct fasteners?

Do I need a special gasket?

Should I just pony up the dough for the FMF mid pipe and silencer? 

A little help for a noob is appreciated. 

Thanks my dudes and dude'ets 

[375hp banshees]

iirc, been a minute, dont think there was a gasket ( not sure) and it looks like its welded twice there.
these are from my cpi's.

fattys look completely different. Not much help, been a long time since i repacked, but seems like the pipe continues inside where its full of holes . gonna be hard to repack now. Does the other end have these caps too?

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