Split planchets are great, but I'm not 100% sure that this seller has both halves. I think a regular 10c has been used for comparison.
I only see 3 images of the interior of the planchet, and all 3 images appear to be identical. On the 3 images, at approx the 12k position, there's a raised 'lip' that protrudes above the edge, if the seller had the opposite side, I would expect to see another image with an incused area that this 'lip' fitted into.
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