Mystery Castagnari 3-row, 18 bass, the "Matris"

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).