Here's what I bought - and an unusually low price (normally £40 or so apparently) - it arrived within a few days and looks fine.
http://www.ebay.co.uk/itm/FORD-FIEST...item46131e240d
Apparently... the Fiesta ones have smaller bore - which improves pedal feel. The ideal is a non-servo Mk1 Fiesta - but they are hard to find - next best is the M1 Fiesta servo - which is what i've linked to above - another option i've seen mention is a Fiat 124 master cylinder (
http://www.ebay.co.uk/itm/Brake-Mast...item484597ba27
Why are you looking at Escort or Mondeo? Is it availability? If so i'll happily sell you my Sierra one from my donor...