Phil your paint code is Lr902 VW grey/white a very commonly used coulor Halfrauds paint match system i beleive in every store now can and will mix it for you on the spot its thesame grey/white used for almost the whole run of T4's my 2000 was the same colour as was my 99 and now my 95 [phew] great colour to match mind [worry not if you happen to watch them mixing it it has yellow/red and grey in it also to acheive this colour] and most paint stockists have it in touch up & spray can ...... versions
If you wish to try to restore it back to original the bset way is to rub as Wireman says right abck to bare metal and apply a few liberal coats of a proprietrary curer likes of Kurust or Rusteleun to th eentire area which will chemically change the rusted area back to solid metal having done this apply by spray can to all sills and the inner lip only of the wheel arches white body shultz followed by several layers of LR902 grey/white paint from wherever you choose to obtain it from - bset to use panel wipe/s between coats to clean and wear latex gloves as every little mark can and will be seen ..... the original finish on teh sills is body shultz painted over anyway so it will be fine ...
Preperation - Preperation - and more preperation is the key however unless you have a well heated and ventelated garage to work in i wouldn't be attempting any of this untill at least April when temp rise enough as all that will happen is that it will not dry and bloom when it does as you will trap a layer of moisture under all coats making it rust even worse than it was only from the inside out
Ps the chrome arches look great on a white one, i had them on my 2000 ser White Noise .....
Look in the Bodywork section paint info is there i beleive ....