They released "thin skin" nitro Jags and Jazzys a few years ago. They're hard to come by now. Pretty much every new Jag/Jazzy/ you come across will be polyeurathane - which don't wear in the same way (don't wear at all more or less). Go vintage however and your wish is granted.
I'm always sceptical of relicing guitars, you can tell from a mile off with all custom shop and road-worn Fenders and in my opinion and it looks sh*t. I've seen some fair custom jobs but why fake it? Just play with more abandon and clean it less. One thing you could do to get a vintage looking neck is refinish it with a darker tint but you should get that done by someone who know what they're doing or you could walk into a sh*tstorm. Better still buy a scruffy second hand neck off ebay and do what you like to it, then you won't devalue the original neck if you want to sell it.
