I made an funny discovery yesterday.
I found the original 365 brochure online. On the first page is a top-down and side view illustration of the vessel. If you zoom in on either drawing (attached), you’ll see “DUFOUR 345” on the side of the cabin top. The 345 designation makes sense since the hull length is 10,53 meters, or 34.5 feet. It makes me wonder if the 365 designation was a last-minute marketing decision and they forgot to edit the illustration.