In the Ishiguro interview, he said that Kawamori had already demonstrated the VF's transformation process out of a paper valk, but that "considering the inflexibility of plastic, a faithful transformation would have been impossible." Or, by Renato's account of Design Works, Kawamori made it out of some sort wood substance and brought it to Takatoku.
edit: Ishiguro also mentions that Takatoku took out patents on portions of the VF's transformation process. Which parts though, he didn't specify. If Kawamori did design the 1/55, I would hope that Takatoku didn't patent portions of his work. My guess has always been that Takatoku did the lion's share of the work and Kawamori polished their prototype for accuracy. Renato, if you have any free time, would you mind going through Design Works again? Now I'm also curious as to how much (if any) work Kawamori did for the 1/55.