Wood's story is true to what I have heard as well. They also had certain models of Martins and Guilds etc.. that they took back to Japan and disassembled to reverse engineer their copies. They did such a good job on copying certain models that Takamine continued to flourish and eventually was able to survive on their own designs as a Company. Up until the late 70's though they were strictly a company that produced more affordable copies of the Higher priced American made counterparts.
Takamine did make different Copies of Predominant Guitar Builders throughout the 70's and early 80's. They copied everything from Martin, Gibson, and Guild to a Copy of a Gallagher Doc Watson model. They made several Guild Look a likes but none of them were true copies as the dimensions didn't match Guilds and they only used solid tops with Laminated backs and sides. They had a 16" lower bout "Guild Look a Like" in a six string version with a flat laminated Maple back and a Flat Laminated Rosewood back, They also offered them in a 12 string version as well. The truss rod covers in the photos posted of the 16" Jumbos are actually fake as there is no adjustment at the headstock on them. They were all adjusted through the soundhole and all had single truss rods. These Guild copies did sound decent for what they were but honestly when compared to the real thing sound like Half of a Guild. I believe the models numbers were F390s, F390MS for the 6 string models and F395s or F395MS for the 12 string models with the "S" designation specifying the solid top and the "M" designation specifying Maple. The problem with most of the Guild copies that Takamine made is that they were pretty much all manufactured with a shallow neck angle so by now most of them severely need a neck reset and while they are cool guitars the Neck reset normally costs more than the guitar is worth.
As far as other Takamine copies of Martins and Gallaghers they sound as good as the real Deal even with the laminated sides and backs. I have a 1976 F375-SH which is the copy of a Martin D35 and it has the 3 piece back made of Laminated Jacaranda or a derivative of Brazilian Rosewood. The "S" designation denotes the solid top and the "H" designation denotes the herringbone binding. I also own a 1977 F362S which is a Sitka/ East Indian Rosewood version of the Gallagher Doc Watson model from the period. That was my stage guitar for years and still sounds great to this day. Overall they are Great guitars for the money if you find them reasonably priced. Problem is that lately people are asking astronomical prices for them and normally for a few more bucks you can buy the real Guild and have much more guitar for the money.
I also own 2 Japanese made "Lawsuit" electrics which are a 1977 Aria Pro II LC 550 set neck Les Paul style guitar that blows away any Gibson Les Paul from the same era I have put it up against. I also own a Full Hollow 1981 Aria Pro II PE-175 Herb Ellis model which is an awesome copy of the Gibson ES175. It also blows every other Real 175 away I have put it up against. Lots of Bang for the buck in the late 70's/early 80's Japanese made gear. When I was a broke gigging musician these guitars were the perfect storm of quality, tone, and affordability. I don't think I would ever sell any of them for any price as they are part of the keep it forever collection to me.