At Tamashii 2016 S.H. MonsterArts showed off the Tamashii Mix MechaGodzilla Poster Version, a figure based on a stylized movie poster for 1993's Godzilla Vs MechaGodzilla by Noriyoshi Ohrai. but there is more to the background of this figure. The original concept of MechaGodzilla had him being made from 7 separate ships each transforming into a vehicle (very similar to the combiner Transformers).
The original plans were scrapped and a two part MechaGodzilla was designed with the upper body becoming a jet, and its lower body becoming a tank, this set-up would end up being used for M.O.G.U.E.R.A. in being able to split into the Land Moguera and Star Falcon in Godzilla vs. SpaceGodzilla. Eventually MechaGodzilla was a single unit with Garuda attaching to him to form Super MechaGodzilla.
The early artwork poster for Godzilla vs. MechaGodzilla 2 drawn by Noriyoshi Ohrai features the Transforming MechaGodzilla. This is notable, in that it is one of the few instances of an unmade kaiju or unmade design for a kaiju appearing in a piece of official media for the completed product. Ohrai's depiction of Transforming MechaGodzilla is the same as the artwork for the mecha created by Shinji Nishikawa, indicating that the design used for the poster was the final design for Transforming MechaGodzilla before the character was redesigned into the Heisei MechaGodzilla.