Entry for September 2019's Guitar Of The Month is now open!
Although not a guitar, I personally have an invention which is currently being reviewed by a mnfg. company. My invention, of course, was researched to insure no infringements. My patent has been filed (prior to going to mnfg co.). My total cost for all the research and development (including a prototype) was about $9600! My understanding is that if your idea has a "25%" variation of another, then you can legally design it. Robert