Use a local trustworthy garage, Ford won't do any more than they will, apart from charge you double for labour.
Why people think that taking their cars back to the main dealers for all the maintenance is better - it isn't trust me, I worked at a main dealer for many years.
You just come away with a considerably lighter wallet/purse from the extortionate labour and dealer parts charges!
Were any of the bolts or connection loose as you were removing the starter?
Had a couple at work with same problems and one turned out to be loose earth wire bolt to the engine that could be seen sparking out, other was starter motor brushes worn (ex taxi).