that thing is looking pretty nice to me, good luck getting it for $500-$600...if u are able to somehow pull that off while this particular F-20 is also listed on Reverb, that would be the equivalent of a "Christmas Miracle!" wave the cash in the face live and in the flesh, hey you never know.
that particular veneer of Brazilian RW headstock overlay is crazy!! look at that! also like I said the bridge is beautiful Brazilian RW (definitely do not alter it!), but the later shape/style- of which many, or possibly most, are typically EIRW. It also has the "Hoboken" truss rod cover...but those later tuners, and serial number 57,xxx... all of these features together are quite transitional. This one is short scale, right? i like it.
keep in mind I have full faith, confidence, and credibility in several professional luthiers and guitar technicians, at this point. A neck reset on a vintage Guild is a major league professional job. even so, things can still go "not as planned" and in those scenarios, the character and ethics of the luthier will come into play- as another forum member learned recently. I am like you, if it is meant to be, it will be...with or without the unexpected surprises that may come along later. If I decide to go for it, I just don't look back. so far, i've been lucky. even refinishing and other cosmetic repairs...they just need to be done right.
the Oxnard M-20 is a great guitar, I have personally played a couple. but it will sound quite different from a 1971 F-20 (will sound a lot like a 1971 M-20!), and with a 1.75" nut width and baseball bat neck profile (and satin finish for that matter), the Oxnard M-20 will feel and play completley different than a 1971 F-20.
if you can buy the F-20 and have it successfully professionaly restored (sounds like your luthier is a safe way to go so far), without issue/drama, and it stays in the cosmetic condition it is currently in, in the neighborhood of $1,500-$1,800 total...vs. a new Oxnard M-20 for $1300-$1,400...it just depends what sound and feel you are going for. The M-20 will just be a player acoustic in its purest form- you will never make any money reselling this guitar during your own lifetime, if you buy one brand new- likely quite the opposite, if anything. this can actually be a good thing, psychologically- gig it, travel with it, warrantee it...share its soul. The 71 F-20 was made to be played for sure, and it should be, but that thing is pretty clean, and while I would never suggest holding back with *any* F-20, this one might be considered investment quality to some, cosmetically. can still use it for anything you want, its just going down a different road than a new M-20.
and yes I also question whether or not this F-20 needs a neck reset at this time at all, a completley different topic.