Hmm. I always assumed Jackson was first. Assuming is bad so I did some Groogling and found this:
According to
Wikipedia the Jackson headstock first appeared on the Rhoads prototype in 1980:
Traditionally, Jackson (and many Charvel) guitars share the typical pointed headstock that first appeared on the Rhoads prototype in 1980. This likely arose from trade dress infringement issues as a result of Charvel's use of Fender Stratocaster shaped headstocks until the early 1980s. Fender's 2002 acquisition of both the Jackson and Charvel brands has enabled the Strat-style headstock to be reintroduced (under license).
According to
this thread over on JCF it looks like Jacksons went into production in '83. The Guild bankruptcy was around '88 as I recall.
According to
The Official Vintage Guitar Magazine Price Guide The Jackson headstock became standard in 1982.
The
1983 Guild catalog I have has the first of the wacky shaped guitars which are the X79 and X82, neither of which show the headstock shape in question.
The
1984 New Guitarchitecture catalog is the first one where I see the very '80s bright pink S284 Aviator on the cover with the headstock:
Of course, I can only make assumptions based on the data I have, but it looks to me like Guild was trying to get some of the shredder market by making guitars with pointy headstocks. I find it fascinating that the early Jacksonesque headstocks look just like Jacksons and then within a year or so they had changed slightly by reversing some angles (see previous post). I don't have the one that Grot posted with the red T250, but I dub that one "the year of the Cake-Knifes" and wonder if it's 1988 which would be around the last catalog before bankruptcy.
As always I'm happy to be proven wrong. I Hopefully by Hans' next book. :watermelon: