I believe that I own at least one whistle from all the makers on C&F
Does anyone know if Peter is around or contact-able these days?
I do not know personally.
What is your opinion on the ethical dilemma of attempting to reproduce or copy a design in this instance?
I have thought about this for some time myself. Here's my thinking for what it is worth.
I live close to the Martin guitar factory. I've been fascinated with Martin guitars for more than four decades now. It started after my first pilgrimage to Nazareth around 1971(?). I currently play several of the instruments produced there and have owned quite a few more besides. I have met Chris Martin and know quite a few of his employees. I like making instruments myself. There are a lot luthiers in the nearby area. Some are former Martin employees. Those luthiers and almost all other luthiers that make flat-top steel-string acoustic guitars owe their start to C. F. Martin & Co and used the Martin designs, bracing patterns and body shapes to get started. Martin even provides materials and tools to hobbyists and small shops to make their own instruments. Few builders have the resources or skills to build a guitar like a top level Martin and none that can do that, provide the type of ongoing customer support that Martin does. Few have ever had an impact on Martin's sales. Those that have had an impact have usually become part of the family, as employees or consultants, giving back to Martin what they have learned. So those relationships are in many ways symbiotic. We all drink from the same well that spring from West North Street in Nazareth.
When I started making whistles, I made whistles from my own designs and used my own methods. Lots of trial and error, the lessons were quick but not the most effective use of time or materials. I read as much instrument design theory and history as I could. I owned most every whistle that was out there too. Soon enough I realized that my designs could be improved and they morphed towards designs similar to what others were using. Aha, that's why they do things that way. There are only so many ways to do things and get a good result. So it is a rational thought to begin by climbing up onto the shoulders of the giants that came before us. The Bonsteel whistle has a bit of other whistles showing in it too. He likely went through similar steps himself. I would also submit that you will not be able, in most cases, to match the results of the original maker right away. And you will see ways to make the designs and methods your own as you progress. So I'd think that making a whistle in the spirit of another maker is a good first step but you should strive (and will likely do so anyway) to make it your own in the end.
Flute (simple system) makers rarely succeed by exclaiming that they make a flute according to their own proprietary design. Although I would submit that most make their own proprietary design. The market demands that the memory of Rudall, Rose, Pratten, Nicholson, et al be conjured up to validate a design. How curious is that? So the modern makers oblige. As long as those revered makers remain dead (and their companies defunct) that situation is ok. So what do you do about a current maker's work? Licensing a design would seem a good approach - like Overton, as an example.
I ramble on.