1) With ColorKeyMask set black on this source as transparent
2) Use this scene from 2006 (resized properly) as the base layer
3) Put the 2004 layer with transparent layer over the old source
It should be something like this (GOUT is this scene from GOUT resized properly, SE is this scene from 2004 release)
Layer(GOUT, ColorKeyMask(SE, $000000, 10), "add", 255, 0, 0)
Worth a try