Here's another new model from Castagnari's new catalog, the "Matris," depicted in maple (also available in Wenge).
It compares to the "Evo," which also has the same treble configuration, 2 voice treble, 18 two-voice bass/chords on the left hand. However, unlike the Evo, the Matris has a curved grille (in a beautiful new pattern) and the dimensions are somewhat smaller, yet still larger than a Benny.
The mystery is what this means for the development of 3-row designs (and especially 3 row, 18 bass boxes). The Rik/Handry chassis has been pretty much the standard in 3-row, wooden-bodied melodeons for over two decades, with notable very close designs like Saltarelle's Ocean and Stelvio's large 3-row. The Benny represents the other end of the spectrum, with an almost shockingly compact size for a 3 row box. Now comes the Matris, somewhere in the middle, along with new mid-sized 2 voice 3 row boxes, with 18 basses, in Saltarelle and Serenellini's lines.
Here is a pic from an Italian classified ad, in which you can see the grille design.
And here is the classified ad (on eBay).