it's a brace for cutting out 'rings' of veneer…..the old veneers that were an eigth of an inch thick or more. Note that the cross bar is fitted upside down as the socket taper should be the other way. The cutters were usually stepped so that they could be reversed and then used to cut the housing edges for the veneer ring to fit into.

This place is like a roomful of Arthur Neguses, amazing

Maurice….interesting reference to your grandfather because the one and only time I have ever seen that tool, (and the reason I know what it is) was in the hands of my own grandfather when he was cutting veneer disks in his workshop during the early/mid 1950's. as near as I can remeber across 60 years the tool was virtually identical to that in your pics. I don't remeber seeing it before or after so assume that he borrowed it for the job. The crossbar and various cutters and pivots were kept in a canvas tool roll. I can clearly remember him showing me how it worked and that he used a flat, leather covered pivot pad held in the square taper to cut out the veneer disks.

…….i forgot about this tool for nearly 60 years but about two years back when I was 'delving' into the methods of 17th C clock makers I suddenly remembered it and came to the conclusion that they must has used a very similar tool to cut out chapter rings and clock faces from sheet brass,…possibly also the actual wheel blanks too. Actually, a tool like this would be quite useful to me now for that purpose.

Is anything really new?

Well, I'm not sure, but I have never come across a reference to LED street lights in Caesar's Gallic Wars …

Cheers, Tim