PhilTheGeek

If it was just P173c, P073a and P072b then I'd suggest it's metallic crap on the gear selector fork position magnets. Simple fix if you're willing to drain the gearbox and pull the mechatronics off as you just wipe the magnets clean. The other 2 being present are more worrying as that points towards breakdown of the mechatronics TCU board in some way. If it had the 34F7 recall done then the oil it previously had in it causes damage to the TCU board causing corrosion and short circuits. If it's had a recall done properly then they should have put a sticker with the recall code written on it, in the spare wheel well next to the existing vehicle spec sticker.

Re-checking I find that I missed that AR was the original part for the Mk1 which was superseded (on 1st June 2010) by the Mk2 BC part. So yours will have been fitted with the AR part but Skoda now supply BC as its replacement (for a bit more than £600. Ouch).