Which famous model of Jazzmaster does the Squier model pattern after?
Classic Vibe and Vintage Modified Squier guitars closely follow the designs of famous Fender guitar models, but of course do not replicate them exactly. Certain things are changed for modern playing style and feel.
A good example of this is the Classic Vibe Telecaster '50s, one of the best guitars Squier makes. While it is true-to-vintage-spec with its tuners and other hardware, the neck has a modern 9.5-inch radius with medium jumbo frets, and the body is made of pine.
Vintage Modified Series from Squier is interesting, because depending on what you get, it will either be a 1970s-inspired design with modern modifications, or it will be a mish-mash of 50s or 60s design with modern mods.
The Squier Vintage Modified Jazzmaster in particular is one of those that is a 60s design with modern mods to it.
As far as I can tell, the Squier Jazz patterns after a '64 Fender Jazz, but just in appearance, electronics and not much else.
In '64, Candy Apple Red (the color of my Jazz) was a finish option along with the white pick guard, so that's period-correct.
With the exception of a deleted lock button on the vibrato, the hardware is very close to what a '64 Jazz is. Same bridge style, same tuners.
The Squier does have "parchment" color dot inlays on the neck. This follows the look of the '64 Jazz as Fender was using clay fret markers on the Jazz then, so they were never stark white even when new in '64. The Squier fret marker material is obviously plastic, but the point is that yes, the fret marker color is period-correct to a '64.
A '64 Jazz didn't have neck binding on it as far as I know, so the fact the Squier has no neck binding is period-correct. I believe Jazzes got the binding in late '65 and a whole bunch of '66 models had it.
I don't think any Fender Jazzes of the 1960s had a "skunk stripe" on the back of the neck. The Squier Jazz does have the walnut (or possibly koa) stripe. However, this is something I actually like, because to me, Fender designs look proper when that stripe is present.
In the end, yes, the Squier Jazz really nails it well when it comes to emulating the look of a '64 Fender Jazz. And obviously, it's also a fine player.
A few more words on the walnut stripe on Squier guitars in particular
Nobody does a walnut stripe on the back of a neck better than Squier. Yes, Squier. Not Fender. On a Fender Mexico or American neck, the satin urethane makes the walnut stripe look milky and faded even when brand new. On a Squier with its polyurethane or gloss polyurethane, the walnut is dark, rich in color and you can really see what walnut is supposed to look like.
I got used to seeing the dark walnut stripe a long time ago with my first guitar, the 1989 Squier II Stratocaster. The neck look and finish on my new Squier Jazz is almost identical to it. It's a tinted tinted gloss polyurethane, and the maple is slightly flamed.
Yes, my 2012 Squier Jazz does have a flame maple neck, just like my '89 Squier II Strat does. And the tint color is almost identical as well.
In 1993 when I got my American Strat, one of the first things I noticed was the milky/faded look of the walnut stripe. It just doesn't look right and never has. Sure, the satin finish feels great, no question, but the tradeoff is that the walnut stripe is lightened in color significantly.
To this day, new Mexican and American Standard Fender guitars (Strats and Teles) that have the neck with the stripe along with the satin finish all have that faded/milky look to it. And there's no way Fender can make walnut look better through that satin finish just because of the nature of what it is. When you want the walnut to really stick out the right way on a guitar neck, it has to be glossed.
Now even though I don't like a gloss polyurethane finish on a guitar neck, the Squier Jazz I have is very, very close to what my '89 Squier II Strat is. The feel of the back of the neck is so close that it's scary, but in a good way. And that's one of several reasons why I'm totally loving the neck on it. Late-1980s Squier necks are frickin' amazing, and the Squier Jazz, even though Indonesian made, has the late-80s Korean build quality to it.
I have no idea how thick or thin the finish is, nor do I really care. All I know is that it looks 100% correct and feels 100% correct.
Is the stripe PAINTED on?
It is true that some people who try to fake a Strat or Tele neck will in fact paint the skunk stripe on the neck, usually with black paint.
From my examination of the Squier Jazz neck, I can easily see the grain pattern change where the stripe is, so it is definitely a different piece of wood. And I seriously doubt it would be a sticker because that would do nothing but add cost to production of the guitar. Squier axes are built with cost-cutting in mind, and since there are already plenty of other Squier axes that don't have the stripe, it would make no sense to put one on the Jazz as it would do nothing but add cost to the build.
In other words, yes, the Squier Jazz does have a real-deal skunk stripe on it. If that stripe is a sticker, it would be the most convincing sticker-pretending-to-be-wood I've ever seen. I'd expect to see something like that on a fake Fender, but this is a Squier, so there's no reason for anything on the axe to be fake at all.