The DVD case was the only piece of 1mm thick household plastic I could find that suited my purpose
it's flexible and nicely bends back into it's original shape.
Although I've een quite busy (always am
except at work atm) I found some time to roughly cut the parts for the back of the switch yesterday and stack them together to give you an idea what I came up with. slideshowgallery
As you can see the "cross" part lies in the slots of the acrylic panel and won't be glued onto it, this way it bends nicely when the button is pressed.
The square shaped piece will be glued to the acrylic so the "cross" part will stay in it's place.
a little piece of plastic from the CD player will be glued onto the "cross" part and press the power-microswitch on the RF board
p.s. One more thing about the DVD box plastic: Beware that this is plastic no 5 (polypropylene) and can't be glued with most standard plastic glues, overhere in the Netherlands "Pattex" has a glue type (rapid) for it which consists of 2 elements: A primer for the surface and the glue itself.
p.p.s. here's a new design sketch: