You r right frank3, the cylindrical shaped thing just behind the prop is Corbetta anti-sand filter. The C 205 s were equipped in series with Corbeta anti-sand filters which were positioned on the air inlet of the compressor, they were shaped stoppers which prevented the sand entering into the exhaust pipes and into the air inlets.
The bottom ones are cylindrical oil cooler. Note the divergent shape of the exhaust pipes and the classical "rings" Veltro camouflage.