Mate... Im really against putting printed decals over an area of a playfield.. i know many do it, but you did ask for advice..
What you can do is just do the red area and leave it at that.. learn to live with the wear on the cards... if you are looking for a pristine playfield, you are not going to get it by adding a printed graphic.. you are also not going to get it by just doing the red. What you will achieve though is a much better PF that can be restored later down the track by someone else for you if you choose to do so.
Or.. do the red and hold out until another PF comes up in better condition and swap over... the original PF could be sold as a restore piece... im always interested in this type of thing for restore. What i and many wont buy though is a PF thats had a decal stuck down as when i try to remove it, ill just remove more of the artwork that really needs to be retained as much as possible.
Just my opinion...
