The entire broiler element assembly should pull out in a single unit from its plug in the back of the oven.
If there's a break in the coil, you'd have to get a new length of it and weave it through yourself, as I doubt any appliance parts or repair shops would bother. I don't know off hand of any source for the insulators.
The most likely way to have it fixed is to take it to an independent appliance parts house and ask if they can place a new radiant tube element in it. They would have to send it out to have this done, but it's usually a one or two day turnaround. I have a feeling this was a common operation back when these stoves were in households across the nation.
The bake element on my mom's '49 Westinghouse was replaced two or three times with a newer radiant tube type. The last time was about ten years ago (she baked a lot). It's possible there is a similar solution for your broiler element.
