Unfortunately, for the older style 2 and 4 slice models '5KTT890 and 5KTT780' .... it is now very hard to locate the majority of the parts for them. We do get knobs and levers occasionally but most parts are now no longer available NLA.
The heating elements have always been so expensive that it is more cost effective to just buy a new toaster.
Please click the link below for the parts list for the Toasters.
Click here for a parts list for 5KTT890
Click here for a parts list for 5KTT780