I recently bought what i believe is a hn white king c melody in slight disrepair. one of the first things it needs to be playable is a neck and mouthpiece. just wondering if you guys think a tenor one should do the trick before i buy

Even though they look similar, a tenor neck will not work. Since the tenor is pitched one step lower in Bb, it is longer than a C melody. That means the neck will be longer and it won't play in tune on a c melody. And that is assuming that you could find one that fits. The likelyhood of finding some other neck that will work is really pretty slim because they are not really interchangeable. There are several factors to a neck: length, taper, tenon size, octave key location, etc. If any one of these are not right, it won't work.

I just remembered that there are a few companies that sell aftermarket replacement necks. Here's one:

http://www.musicmedic.com/catalog/products/part-gh100.html

If you look under the tenor necks, a King C Melody replacement is listed, but they are not cheap...