The perforated inner skins on the nacelle front are very efficient at killing the reflected buzz from the fan. They make a huge difference to the noise footprint.
By Nozzle fence I'm not sure what you mean. At the back, the nacelle of a CFM Boeing 737 has a spine under and over the engine. The nacelle is constructed of a front section, bolted to the engine fan housing and the outer and inner doors hung from the top mounts and latched at the bottom. The Thrust reverser cowls are the rear section, which slide back and forward and run in tracks top and botttom. The lower faired lip at the rear is the cover for these door track mechanism. At the top is also the heat shield for the pylon.
You have a single large aerofoil on the side to creat a vortex over the leading edge at high angles of attack, and a smaller blade in the upper inside to deflect a small sprung hinged section of the outer Kreuger leading edge flap when thrust reversers are deployed.
Regards,
RVF