@Phil, The answer depends on how the first patent is written. If it was "bulletproof" then there may not be a patent. I can remember people trimming edges of laminate with rat-tail files, but that doesn't mean everyone was doing it the same way. For a patent to be "bulletproof" it must have numerous claims that are as close to "all-encompassing" as possible. Patents with only one or two claims are usually easy for someone to get around. In the past, I have actually "lost-out" and "benefitted tremendously" by the ways some patents have been written. Patent writers need to be imaginative to get as many claims accepted as possible, but getting thorough patents can take 2-3 years after all of the USPTO requirements are met. I do not know which company first offered which products first, but that, in and of itself; really doesn't prove anything.
OPG3 Tweak everything!