Contact Tomturbomatic on here. I know he has mentioned that he had access to the more rare pre-1960 3-wire radiantubes. I bet he could put you in touch with the later 2-wire versions that were made up until the late 1970s.
If you are at all mechanical, you could go on a hunt for another 1960-1975ish stove for parts alone. There seem to be quite a few "Flair" ranges out there that people can hardly GIVE away. All of those burners would work on your stove, the only thing you have to be careful of is the "Speed-heat" 6" version of this design which is made to operate on 120 volts. It can be safely used on a non-speed heat stove and control, you just have to make sure that you wire it at 120 volts instead of 240.