Rockhopper,
I don't claim to know anything about patents other than what I have gleaned from patent searches and personal observation. I acknowledge that I am likely niave in my interpretation of patent law. That being said, here is my take on things, right or wrong.
I make musky baits and there are literally dozens and dozens of baits that look like mine, swim like mine and are finished like mine. These baits are here today, were here yesterday, a hundred years ago, and will be here tomorrow. What I make is not "unique", or possess or contain an attribute that could set it "apart from" thousands of others produced before it.
I don't prescribe a builder on this site take a Lucky Craft lure body, paint it and sign his name to it. But, if you take the shape of a Lucky Craft, make it from wood, give it your method of weighting, paint, finish, etc., and sign it, I sincerely doubt anyone is going to try and take that to court...and that is essentially what all of us and thousands of others in the market (including Lucky Craft, Rapala, Heddon, etc.,) are doing. If you haven't done so already take a look at antique lures, there isn't an idea on the market today(with the exception of some high-tech rattles and weights maybe) that hasn't been around for 50 years or longer.
I think too it depends some on the product you are talking about....there are probably some products on the market in which the patent ties are very tight and any production along similar lines would be unacceptable. But we are talking about fishing lures, lures that have been manufactured in the same way for a century or longer. The patents on these concepts have long since expired and thus open for production by all. Unless a builder is copying a very "unique", i.e. "one of a kind", feature of some lure or lure type held under a current patent, I think a company would be hard pressed to show infringement. How can you be infringing on something that has been made for a hundred years in every shape and form we currently use today? Now if you take a lucky craft bait and send it off to China and have them make you an injection mold for that bait identical in every way then I would agree you are likely violating a patent.
Kind regards,
Jed