Hi,
Here's a good link toward headstocks:
http://thettablog.blogspot.com/2005/01/rec...ess-rights.html
And as some have posted "trade dress" is the issue. Patents expire after 17 years (before '96 I think) but now 20 years after filing.
I am a guitar builder and have applied for U.S. patent protection. I do my own patent work. Nothin' to it.
Also trademarks do not expire as long as the product remains for sale.
Anyway this looks like a cool forum, glad I found it.
Bill Guess