Neck shortening mod? (Skeleton in the way)

I want to shorten the neck of my DD but the problem is the internals of his neck skeleton are in the way. I can't really experiment too much as it's a Len body and I dont have a replacement chest piece. I trimmed the vinyl about 3mm but his neck is still too long. I DON'T care about the resell value of the doll, I just want him to look right. Does anyone have any suggestions?

You can replace the neck joint part of the skelton with a custom type using a Parabox Toy Skeleton which can be made shorter.

 

See my friend's blog: http://blog.doll.cafe/2016/10/custom-neck-piece-prototype.html

 

Parabox Toy Skeleton: https://paraboxshop.jp/index_en_jpy_214.html