Can I ask why you think your resistors are bad as they are usually unlikely to fail.
Plse look at this youtube video if you would benefit from some education on the topic.
https://www.youtube.com/watch?v=Q-i0tytSYIM
This Vapormatic site shows a number of different John Deere resistors.
https://www.vapormatic.com/tractor-parts.ashx?descsearch=blower resistor#part_list
If you are still stuck I would go to an auto wrecking yard. Preferably one of the older ones who will go and look in the junkers for an item.
I think the heater fan resistors are very similar between car and truck makes and tractors.
The resistors work by using up some of the voltage being supplied to the heater fan by converting it into heat which is sucked up by the air circulating in the heating system ducts.
The full speed position bypasses all the resistors so you wont make your existing fan run any slower when it is on high speed.
At the intermediate speeds the resistors are used alone in some settings and perhaps even connected end to end i.e. in series to produce an even slower speed.
The resistors will look like coils of wire that glow red like the element in a toaster. these are not electronic device resistors.
Do not operate or power them unless they are in front of a fan to keep them from over heating.
How many speeds does your current system have? At the wreckers ask them to find resistors from a system which has the same number of fan speeds.
You may have to alter the hole in the tin work to fit the new resistors.
Dave
M7040