I think the London assay office just really likes cats! both the Lion passant and the Leopards's head had already been born there, Leo makes perfect sense as the third kitten in the litter.
As to the upside down orientation, generally it is struck this way, but I've seen it right side up in some reference books. Perhaps just poor astrological knowledge on the part of the punch stampers and this orientation became traditional.
For easier identification, I've gone and made a separate page of the Import Marks in one grouping. ->
British Import Marksps. If anyone has an image of the 1904/5 London Sun or Sheffield Arrows, the contribution would be appreciated.
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