Based off of the Everymac pages for the 2007 and 2009 20” iMacs, I’d say it just might be feasible. If you’re willing to open the 2007, you could compare the connection cables as seen in Step 8 of the 2009 20” iMac teardown. If they look similar, it might be worth a shot.
Though before you open anything, take a peek at this page to see if you can find anything that might help in your case. If you know the EMCs then it’ll help you determine compatibility of screens like this one.
Hope this helps!