In 2009 Tony Fisher build two Siamese 6x6x6s puzzles basing on V-Cubes, one with a black and one with a white core. He placed an auctions on ebay for one of the puzzles with the colour of the the winner's choice.
I won the auction and decided for the white body version. Tony extended the center pieces a little bid to take care of the stickers of the inner pieces, which might otherwise be destroyed during the twists of the third layers of each of the cubes. Although the central pieces do not have a perfect square shape anymore, the result is optimal: the layers do not hurt adjacent stickers during twists.
Tony Fisher stated, that he wants to keep the second left puzzle for himself. Because the auction result did not went into ranges, which make it interesting to create more puzzles of this kind, these two ones might be the only ones ever made.
For anybody having experience so far with Siamese 3x3x3 only, the additional inner and outer pieces which have to be adjusted are a challenge. As any "standard" Siamese puzzle, this one limits the dimension of twistable layers to two.
Size: 6.9 x 10.4 x 10.4 cm