Hi Craig,
Warmoth make 22 fret necks that fit a standard tele so you should be able to ge the intonation ok (other than the normal issue of tele's with 3 piece bridges). The other comments on the neck are all accurate, 22 frets, separate fingerboard, neck truss rod adjustment, 60's rosewood decal, skunk stripe with separate fingerboard and Fender headstocks chamfer off the bottom into the neck, not a square edge all the way round. None of these are Fender features. My guess is it is a Japanese or Korean neck. The body looks fine, though it is a top loader, so not as much ring. If you like it £150 isn't a bad price.
As music shop owners go though, I would have to say that he shouldn't be in the business. If he can't tell a 50's tele neck from a 60's, let alone a real Fender from a fake he can't have much idea. Also, if he really thought it was a refinished 50's/60's neck, then the cost should have been in the thousands not hundreds.