As always, your help and expertise is greatly appreciated.
This requirement is not very hard. It only requires some setting up as the original twisties script expected images to be switched. But nothing a little find and replace can't fix.
Can you email me directly at: contact [at] wvanweelden [dot] eu? I have whipped up a sample script and project. I'd like to send it to you to see if it works. If it does, I'll publish it.