HI "Viking", welcome aboard!
Serial number charts are known to have errors and omissions, and the "JF"' models seem to be particularly prone to the problem, possibly because they were introduced at a time of frequent ownership turnover at Guild? (It's just an idea that occurred to me recently)
We also know those serial numbers seemed to get "re-defined" during the course of production, and I'm going to take a guess that your JF650524" could easily fit in the 1987 slot shown on Guild's site.
http://guildguitars.com/wp-content/uploads/2014/08/history_of_your_guild.pdf
Remember the s/n's shown there are supposed to be the
last ones for a given year, and if they
changed formats during the year it could explain why yours is lacking the expected "JF6512" prefix.
Notice the regular "JF65M" 's from which the 12 is derived show the "JF65" prefix with 0031 being the last one they have record of for the 6-ers, in '87.
Seems kind of unlikely they only built 31 of 'em in '87, but I guess it's possible, depending on
when they started building 'em.
I'm willing to bet they simply started stamping the 12's with the 6-er s/n sequence until they decided to give the 12's their own sequence, which then gives the last known number for them in that year, and gives the impression they were ALL "JF6512xxxx".
Another possibility is that they simply screwed up when they assigned JF65 type s/n's to some 12's. That's been shown to have occurred in other cases on other models.
I recall another member recently with a similar question, and our member Hans Moust who's our favorite go-to resource for questions about s/n dating was able to set him straight.
Hans prefers to be contacted at his website if he doesn't see this and answer within a day or 2:
http://www.guitarchives.nl/guitarsgalore/
For your JF3012: the lists actually end in '97 even though it's implied they cover a longer period than that.
For both of the 12's I think you'll also find a date stamp on either the heelblock or underside of the top for the JF6512, and the neck heelblock itself, of the JF30-12, although Westerly did discontinue that practice late in the game, but I don't remember when. I think '98's still had 'em?
The heelblock stamps can be a little hard to see, for example, it's on one of the bevels in my D25, and is only visible at just the right angle looking into the soundhole.
Those dates precede the actual completion date of the guitar by at least a few weeks to a couple of months depending on how popular the model was.
That has all the hallmarks of guitars that were "recycled " through Fender's liquidation channel, "Musical Instrument Reclamation Corporation":
http://mircweb.com/
Is their an s/n visible under the "USED" stamp?
That would indicate a Corona-built model, '02-'04. MIRC put the stamp there to mark guitars that were sold expressly without warranty.
Over the course of the closure of Corona and Tacoma ('05-'08) some unsold inventory was liquidated through MIRC that may not have even had any problems, but because they were being liquidated at such low cost Fender needed to be sure to protect itself from future warranty claims.
Tacoma saw the cessation of stamping s/n's on the back of the headstock.
MIRC normally put a barcode stickers somewhere on the guitar, frequently right on the label to obscure the s/n, but it also ID'D the guitar for
their purposes if needed.
So I'm guessing maybe the label was removed by somebody who started by trying to remove the barcode sticker.
As for soundhole size, we know they introduced some new specs on F512's in Tacoma and that might be one of 'em.
Oh, does it have a compensated saddle? That was a Tacoma innovation, assuming it's original.
Or
if it's got a single adjusting nut under the truss rod cover, that was another Tacoma design introduction, a single truss with dual flanking rods in 12-ers, introduced around '07.
I discount the possibility it's a New Hartford F512 because we've seen so few reports of
any New Hartfords being sent to MIRC.
In fact it was a surprise to many of us when we first heard of it a couple of years back.
Also I'm not sure they'd even built any F512's yet, in '09.
Edit: I see Gardman got his post in while I was still composing, but you can see we both agree on some "basic concepts".
Somebody oughta be along soon asking for pics, too.
:glee: