Looks like Mike L. of MultiMarine is the US dealer...he's the guy that came up with the L7 "Franken-tri" (cobbled together from Nacra hulls). He was also a Corsair dealer and a Catri dealer in the past.
The M23 looks interesting and fills a niche in the market for a smaller/more affordable trailer tri.
If anyone is interested... here is a link to a good write up about a recent sail of a multi23- even with an I20 for comparison... there is a PDF halfway down the page regarding the sailing... here yes, a dealer, but he has been around cats and tris for a long time...