Am I right red blob goes into red arrow , green into the green arrow and the backbox in the orange bit?

Is it a simple bolt old one off, bolt this one on job?
Raceland 4-2-1, Supersprint centre section with silencer, Magnex backbox

Is it a simple bolt old one off, bolt this one on job?
Raceland 4-2-1, Supersprint centre section with silencer, Magnex backbox