To my knowledge, nor have I seen rebuild kits for either the door remote operator or new splines for the handle.
I replaced my remote operators with aftermarket ones and they work great. There hidden behind the door panel so nobody would know the difference. Your best bet for the handle is to replace it with an old original. They come up on eBay quite often or place an ad here in the “Truck Parts Wanted” forum. I'm sure you’ll get some results.
Here is a link to the remote door latch operators.
LeftRight