From Classic Ford Feb 2015:
"Many Capri owners will have suffered from a one-speed heater thanks to a knackered resistor. With new ones unobtainable and good, second-hand units hard to find, the news wasn’t good, however, Trev at Quoyloo Garage now has brand-new heater resistors which fit directly into the heater box as per the originals but with modern technology. Good work!"
Wombat is exactly right regarding using a 44¢ ceramic resistor instead of £45 worth of "modern technology". Furthermore, there is no harm in using one with greater wattage; it just means it can handle more heat dissipation (should it need to).