I've found exactly what @nilebodgers says r.e. the one Chinese neck I bought.
The whole thing is oversize, but if you did buy one RB, a woodworking man such as yourself may be able to slim the whole thing down by a mm or two?
I found the extended heel that Nile also mentioned, is a hurdle to playing chords or whatnot on the high frets.
Here is a pic of the behemoth, next to a more normal neck:
I sanded the heel end to fit in the body, but if all the Chinese necks are like this, as I said, in my view it's oversize by a fair bit in every dimension. 👍