I've looked many places to find a replacement for the remote door latch return spring on my FSJs. I found one that works for me (not an exact replacement), but the orientation is correct and works well on the driver's door remote handle. I also found a manufacturer who can remake the spring for a bit more cost.
The substitute spring I used is a 1941-1946 Dodge Plymouth Chrysler Packard Hood Trigger Latch Repair Spring. I've included some pics of the substitute spring compared to the larger, original spring. There's also a pic of the substitute spring installed in the remote door latch assembly. These springs can be found on ebay and other sites. Best of luck.