Released in 2012 by Kotobukiya is the 1/35 scale Gunhed from the Gunhed movie that came out in 1989. The scale model can transform from G1 mode to G2 mode, sort of like a car mode to a semi-upright mode. After seeing the 507, I can’t help but wonder whether this was the inspiration for the Hildolfr?
Construction Manual & Color Guide for the 1/35 Gunhed Unit No. 507 was translated to English from the Japanese manual posted at Dalong’s Gunpla & Model Kit Review site. For the meaning of the symbols found in the model kit’s manual, kindly refer to this post.