A 2 mix putty...
Just to share my experience. I find this putty is the best among the group I used (Tamiya, Squadron). I can apply this in a smallest hole without excess. easy to apply, you dont have to press it so much inside the gap. And it dry fast. You can start sanding it within few minutes. When this thing dry, its harder then a dried (tamiya) paste putty. So when applying this stuff, I try not to put too much. As much as possible I apply it at the same level as the finish to reduce sanding time.
http://www.hlj.com/product/ALG001