"What you will see are the anti-biff bars behind each flipper to prevent bounce backs or death saves. Some Stern games have them and some don't. Ripley's didn't but Lord Of The Rings did."
http://www.pinballnews.com/games/elvis/index4.html
Yep, that's them! I have a new playfield which has the holes for them already but the current playfield is missing them, though it must have had them at some stage because the holes are still there.
