🚀 go-pugleaf

I am trying to create an applescript to scale a spread in InDesign 2.0.2 to A3 size. The spread is currently 2 A4 pages, but I want to scale it down to be able to fit an A3 page to print.

This is all I have been able to write yet, with scaling figures of half the current size. But this only scales the page items, not the spread.

tell application "InDesign 2.0.2"
   set myDoc to active document
   tell myDoc
     select all page items
     set mySelection to selection
     if scaleSchoice is equal to "A3" then
     --scale mySelection to A3
     scale mySelection horizontal scale 50 vertical scale 50 with considering current scale
     end if
   end tell
end tell

Thanks for all your help,
Liz