I have a 18 year old Viking refrigerator that needs a new heat exchanger and evaporator. According to the repairman, Viking only has a limited number of evaporators available, so they've jacked up the price to over $1000 for the part alone. The repairman says that Kitchenaid and Whirlpool both made the same refrigerator - replacement parts are much cheaper (around $200 for the heat exchanger), so if I can find find the comparable parts I can save a considerable amount of money. Is there a listing that cross references these manufacturers? Thank you.