CNC wouldn’t save time, you’d be designing a program on a computer as opposed to just working the wood by hand. Unfortunately, your best bet is going to be finding an original. You can’t just clone a hand made item. It just doesn’t work that way. That’s the craft behind it. I guarantee, if I had the exact data, recipe and material to build one of your JMR cane rods, and I was a proficient rod maker, I would NEVER be able to build that same rod. The feel would be different. When you buy a hand made item you’re paying for that maker’s FEEL and CRAFTSMANSHIP. Because it’s unique to them and it’s not realistic to replicate. Even a master’s apprentice’s work will be considerably different than the master’s work.Having gotten rid of all my B&Ws abd Meisers for a stack of JMR boo I'm not advocating the easy way out as I'm severely lighter in pocket and it's taken 10 years.
But we wsnt to clone a Grant rod not copy one by planing it. You could spend dozens of hours on a hand lathed rod then just have to chuck it away. And you'll probably have to do dozens to replicate the frequencies. I'm sure I'm way oversimplifying the cnc (I'm a simple guy) but why not use tech if we can to save time and health?