Tamashii/Bandai has officially announced and revealed the S.H. MonsterArts Showa Mechagodzilla figure. They posted it on there blog along with box art for the Mechagodzilla and Godzilla Poster Versions (image at below). Not much info was given other than to say full details would be coming soon, more info as we get it.
Update: the figure will be 9,720 yen (approx $88 US), and will be released Jan 2018. Info comes via a magazine scan (at bottom) but should be updated on the Tamashii website soon.