I needed to replace a front window winder on my County ( refurb project) and these are around $90.00 each. I had a rear one from a previous vehicle & found that with a 40minute job with an angle grinder you can easily adapt these. Rear doors don't even sell on ebay.
Here is the sequence.

Front winder ( it's stripped so its not engaging the winder handle)
Notice the arm extends away from the gear.



Here is the rear winder, notice the arm is kinked & goes over the winder, not away.This is because the rear door is narrower.



So I want the gear mechanism which is actually identical. Cutting off the rear arm, but leaving the centre bolt. Drive out the locating bolt as shown.



Cut close to the bolt



Then grind off the front arm from the stripped gear.Also drill out the bolt off this one.



Drill or grind out the hole so its larger than the rear bolt. & place over the new(er) gear.Obviously facing correctly. Notice the lug & corresponding twin holes.



Put in place & weld it up. Simple.





I reckon Defender would be identical.
I love jobs like this, lets see 40 min saves $90 that equals $135.00 an hour tax free !! - Easy to see the Scottish blood
And, it works a treat