Fitting new CD/Radio unit in Peugeot 406?

Help

I am aware I need a fascia adaptor for a single Din unit and I will also need a steering wheel stalk adaptor for remote control when driving. My dilemma is this...
Is my Peugeot 406 model, first registered Oct. '04 2001 (51) really a post September '01 spec. or could it be a pre-Sept. spec. held over for a month or two. This is crucial because there are 2 potential stalk adaptors PC99-X24 or PC99-X44???