gmanmcusa you do not not want to use copper. It will either melt or shorten out internally and become a fire hazard. What you do need is some high resistance wire. The best would be what has been used for heating coils in toasters, which is NiChrome wire. An 80/20 alloy wire (80%Nickel/20%Chromium also called NiChrome A) would work. With that you are looking at a melting point of around 2,550F vs Copper at 1,980F. Resistance of Copper wire (2ft) is 0.164ohm versus NiChrome at 10.16 Ohms/ft. Stick with a 32 gauge wire. If that gets to hot you can go to a 30 gauge.
I checked my old toaster (restoration project and not as old as yours) and it has flat wire, but I am sure that the round will work for your toaster as well. Let us know how it works out.