Buckbrush:
I haven't seen Stephen Dodd Hughes' book, but just for the record, 'arcaded fences' get their name from
the arched entrance to a typical English arcade in Victorian times, and look like this:

That Tolley has quite unique carved fences, part fluted, part beaded, perhaps part arcaded, certainly 'special' as Daryl says!
The fitting of the Giant Grip third fastener does not lend itself to 'standard' fences, that's for sure!

Again, marvellous gun Sarge! Thanks for the extra photos.