Hello @ all.
Unfortunately Mr Anthony Carter died in 2003... so we won't be able to contact him in regard of the marking.
You won't believe how many "clearly marked" weapons are hard to identify.... for example: the above mentioned "PR" marking on the ebay link.
Perhaps someone has a book on belgian sword markings, which could help identifying the "C.G".
The point LOOKS original, but we are not able to verify it... so we must take the most probable solution to this problem
All the best.... and keep looking/searching.