Can you post a pic of the body?
You can buy 'genuine' replacement Fender parts off ebay from people like 'reliablefender' or 'stratosphere'. Alternatively you can buy replacement parts from Allparts or Stewart Macdonald ( StewMac.com, I like them because their website has lots of specs to check you're buying the right thing, as well as 'Free Information' on a number of topics). For custom necks Warmoth and USA Custom Guitars seem to get the nod. Spend time thinking about what you want in a neck - apart from the obvious things like wood and headstock shape there's back contour ( eg 'C','U','V' shape), radius ( 7.25", 9", 10"-16") , thickness ( measured 1st fret to 12th ), tuner hole diameters, nut slots etc.
Oh, like all mutts it's quite likely that only the owner will love it. So don't expect a decent resale value.
A mutt is for life, not just for Christmas.