So I'm kinda planning a custom that I'll need some help with. Specifically, the quickest, easiest solution.

I want to make a G1 Rewind figure (non-transforming) out of this...

(4 inch tall figure, not the Figma)

My plan is simple, in my head anyway; I want to get some kind of clay/putty that I can easily just apply to the figure to bulk out the body, and make a new head. I, however, would prefer something that is as simple as that; No crumbled mess, no heating in an oven, something clean and easy to work with for beginners like myself.

I could swear I've heard the term "Epoxy putty" go around for kitbashing, but I can't find an exact result. I also only think of epoxy GLUE in this case.

Any help would be appreciated.

 

Hm, you might want to look into Aves Apoxie Sculpt. Personally, I've heard nothing but praise for it and seen some pretty sweet sculpt work done with it (this is but one example: Classics Prowl gets a bodylift) and there's even a "intro" of it by Jin Saotome: http://www.tfw2005.com/boards/tutorials-how-tos/214512-whats-apoxie-sculpt-glad-you-asked.html.
Hope this helps.