Hasta La Motion!

total noob question here. i’ve looked all over for an answer dealing with keylight and transform, but i get one or the other. nothing dealing with shooting greenscreen and then scaling it down.

i have a scene i’m shooting stopmotion for that has a spinning tower in the foreground. rather than spinning the tower while i shoot the rest of the scene i shot the tower against green screen and have keyed it out successfully with keylight, but when i try and scale it down to put in the foreground, i either get that damn "black outside" option or just stretched pixels on the sides and a black top and bottom.

what do i need to do to see my scaled down image overtop of the rest of my animation?

Thanks.

Timmeh.