Adopted kitten w/previously broken tail--should it be docked?

My grown son's cat got outside and got pregnant before he could get her spayed, and she gave birth to 6 kittens on April 1, one of which was stillborn.  Someone locally had 2 kittens whose mother refused to feed them, and I offered to let us try giving them to my son's mama cat to nurse since her babies were only 12 hours old.  The adopted 2 kittens were 10 days old.  The mama cat did "adopt" the much bigger kittens immediately and has treated them like her own, taking good care of them.  However, I just noticed today when I came by to check on them that one of the adopted kittens must have had a previously broken tail when he came to us. The kittens have never been moved out of a closet that stays open, so there is no way it was done since my son has had him.  It is broken in several places making it shaped like a zig-zag, and it feels like it has already healed this way.  My question is what to do now?  I don't know if the kitten has feeling in that majority portion of his tail that is broken, but it does appear that he has no control and cannot move any of it other than at the base where it attaches to his body.  With him being about 18 days old, I was wondering if we should attempt to dock it, leave it all broken and misshapen permenantly like it is, or what?  I have read about docking puppy tails at home with the tying method, but I certainly don't want to hurt the cat or do something wrong, but neither my son nor I can afford something like this with a vet, especially since it isn't lifesaving or totally necessary.  We have to save money to take care of them, find them homes, and for neutering/spaying if we have to keep any of them.  I do have post-graduate medical training for humans and a bachelor's in zoology, so I can understand all of the medical issues regarding doing something like this at home if it would be better for the cat's quality of life (in the event that he cannot feel the tail and might harm it worse due to this fact on down the road) and asthetic reasons that might help him with finding adoption into a new home.  Thanks for any advice and/or instruction on this matter.

Please do NOT attemp to do an at home tail dock. I work in rescue and have seen firsthand this go horribly wrong.

I would hold off and wait to see if the kitten has or gains more control of his tail. Perhaps when the kitten is neutered a tail dock could be done then if needed.

We have a 18 mo old kitty in the rescue that we got at 6 weeks of age. He presented with a broken tail (about 1/3 from tip) and that portion of his tail flopped over, so it looked like his tail was folded in half. He had full blood circulation in his tail. Around 9 mo old, he figured out that he actually COULD move the end portion of his tail. Not sure if there was previous nerve damage that healed or what. But, he has no issues with his tail.