I think that people have got to stop fishing for this "Martin Lawsuit" connection to every Japaneseguitar made in the 70s. The D28 was SOLID wood and just about every "Martin Lawsuit" guitar whether it be Takamine, Yamaki or Mr Miyagi is made of laminate (fancy word for laminste). I own a Sigma and a Goya which are made by Martin in Lorea. Great guitars . . .but plywood with solid cedar/spruce soundboards. The MArtin D28/18/35 are different. Takamine simply stole their bracing patern. These guitars are more copies of the Martin "X" series which retails around $499 US.
I plan to offer $100 for a Yasuma. That is what the Sigma, the Goya and a nice melllow little Seagull all cost me. My Takamine which is new last year and actually IS solid mahogony, is nothing like a Martin.