Shell extension (can't change the background of the panels):
h t t p : / / forum.xda-developers.com/showpost.php?p=4664016&postcount=285
This however seems to be more simular to your handywork (the backgroundchanger):
h t t p : / / forum.xda-developers.com/showthread.php?t=604146
I'm using that to change the background of the panels and it works with MS 3.5.3. on my HD.
I am glad someone was able to pick up where I left off, I would suggest that anyone still following this thread go check out both of these pieces of software (especially the second).