Marmit's coming out with a detailed figure of Godzilla '73/Megaro-Goji (a personal favorite of mine) for their "Real Sofubi Kit" series!
http://www.marmit.co.jp/tuhan2/rsk-006b.htm
It looks strangely fat (weird angle, maybe?), but still good! I've got to see the figure in its entirety.
Oh, BTW, a while back, Marmit made this figure for their "Monster Heaven EX" series, which I thought you'd really find interesting (if a bit weird)!
http://www.marmit.co.jp/tuhan2/kt-159a.htm
That, BTW, is Gou Nagai's Machinesaurer (Mashinzauraa) from a manga he did in 1977, entitled
Machinesaurer! It didn't have a TV series (which is a shame), but it did have a magnetic die-cast toy by Takara, and a tie-in theme-song record! (The song got remade in 1998 for the album
The Legends of Mazinger.)