Hi Luis!
Sorry, but in fact it is my last version.
Of course there are a lot of still unemulated chess devices, but they would require new hardware drivers (which only MAME developers could write), and it seems they are no longer interested in new chess emulations (as I wrote I've sent them a few new ROMs, but there's still no reaction after a few months).
And the bigger problem is, that the current MAME version is absolutely incompatible with the older versions that I've used, and I'm not keen on rewriting my additional code for all existing drivers (more that 150!) for current MAME versions.
Well, 'Internal Layout' is the code integrated in MAME's original driver, but it does not support chess pieces or any special functions, so this choice is absolutely useless IMO.
'External Artwork' is my improved artwork with a better board (sometimes), pieces and adding special functions (e.g. setup mode etc.).
'Realistic Artwork' additionally has a prettier chessboard (either a photo or a 'handmade' picture), but it still has a board and pieces in 2D, because I (and most users of CB-Emu) prefer a 2D view when playing chess on the computer.

Of course you can add an additional view (e.g. your 3D artworks) by simply writing a new code block in the '.lay file - you just have to add a 3rd section like this:
Now you'll also see your 3rd layout '3D Artwork' in the menu 'Options > Video' and can choose between all 3 options.
If someone really wants only the 3D artwork (I doubt that there are many here ), then the easier way is just to create a subfolder within 'artwork' with the name of the device, and put all necessary file into this subfolder - this is the method I've used in my previous CB-Emu version for the better 2D artworks (before I combined them in one single ZIP-file in the current version), but this will not allow to choose between the layouts, because the subfolder has priority over the ZIP file with the same name.

Regards,
Franz