Ok cool, you might find it useful then. Some things worth knowing:
- Find it on Ebay, like Milliput. I get mine from same supplier on there somewhere.
- Costs a little more, but nothing crazy
- It's a two part epoxy clay that comes in a blue component and yellow component. You just cut off a bit and roll between your fingers to mix it.
- It air cures in something like... i dunno, 45 minutes or so? So you have some working time before it starts to set. Mix small batches at a time, not the whole supply
- Does not dissolve in water, so you can't do the milliput trick where you add a touch of water to smooth out the surface on greenstuff alone. BUT when you blend them the mix retains this milliput property, which is a bit neat
- Milliput, when dry, has a more rigid, brittle feel. Greenstuff has a bit more give so in cases where Milliput could crack and break greenstuff might absorb a bit of the force and not break. It doesn't really chip like Milliput can.
- Sculpting tools are useful. Metal or silicone tipped, can be obtained at fairly reasonable prices on Ebay. Keep them lubricated with plain water or something vaselin-y is a good way to keep the clay from sticking to the tools, also for your fingers as you mix and handle it.
- Trivia: it's in fact the very stuff many original models are sculpted from before they move on to be production cast. It's the "real McCoy", if you will
Other people may have more tips for you as it's a popular thing.