I've just replace the starter on my silver top 2.0l Zetec with a new Polish one, cost about £70 and seems to work fine, from my local Autoelectrical specialist in Exeter, but don't know the number, no dout could check. The other option is to have your existing motor rebuilt, I had my old one refurbed and keep it as a spare, cost £45 from the Battery Centre in Bridgwater.
Good luck.