Early Fairphones were not necessarily designed for repairability. That is a principle that has emerged significantly in the last few iterations. The FP4 was the first that was really designed and marketed as fully modular from what I remember, and parts are still available.
For the American piece, the FP6 was the first available from OEM in the US.
I still have various spare parts of my fp2: screen, camera, battery. This was in 2015 and it was modular and repairable. For the fp1, it was possible to replace the battery.
Here are the ones for the fairphone 4: https://www.fairphone.com/shop/category/spare-parts-4?catego...
I however couldn't find the ones for the fairphone 3. The fairphone 4 is from 2021, which is not that old.