Joe, you can maybe use some air drying sculpey for the finer details on the Body or so. There are so much really good sculpting compounds out there, I have tried lots of them. Due to the fact that I sculpt mostly in small scale (means 54mm or 75mm, I have done one Alien in 1:6 for now but thats all in bigger scales) I have to use sculpey which is, hm, more than older chewing gum (without the stickyness) to hold all that ultrafine detail.
I love all that Alien Stuff and I go crazy when I read something here about my favorite figures, hehe, so your dogbuster fits nicely in. But I guess that you are a sculpter who does not stick 100 % to a given designl and feel free to improve and add own ideas to a figure to make it more interesting. That´s fine, too!
Frank
