Ducane "take it or leave it" ele...

I bought 4 "take it or leave it" electric grills for a part time work 3 years ago and all 4 of them are out of commission for 2.5 years now, the electrical cable that one end plugs to the electrical outlet and the other end- that has a pin and the temp. control knob- plugs to the grill's heating element had burned out on me on all 4 grills at least 1 time. Better late than never, I still need to use these particular grills if I can make them work, and now that I discover this forum "FIXYA" I would like to see if anybody can help me to find the heating elements and the power cord with its control knob for all 4 grills.
PS. I heard that Ducane discontinue this electric model and some of its subcontractors sell the appropriate gas parts to at least convert them to gas powered units but for me it does'nt work as i need to work them indoors where gas use is prohibited.
Please help
Thanks in advance.
Emmaniuel