Very interested in this thread. Chas Bowerman was my grandfather, who died before I was born. My mother, who worked with him died in 2010 but had a collectors licence as she had two or three of his guns (non viable) which were sold on her death. One I recall had the three trigger configuration. I still have a few of his tools, including a micrometer. I'd be interested to hear of any of his guns still in existence.