Mr. Bell may not have made it, Argus, that was just a plausible suggestion. Whoever made it knew his way round both metalwork & woodwork, I reckon, both appear to be of a very high standard, so a patternmaker would be my first suspect. It may have been a mate of J. Bell who made it for him, without a lot of searching & a lot of luck, I suspect we'll never know. A lot of very well-made one-off tools have been shown in books & forums over the years & in most cases there is no maker's name to be found on them so unless there is a history of possession, they remain anonymous. I reckon whoever made it
should have put his name on it, it's very nicely done & something to be proud of....
OTH, stamping your name on your own tools as the owner was very common a hundred years ago - they cost a goodly proportion of your wages to replace so you didn't want them disappearing into someone else's kit!
Cheers,