If the Golden Tee overlay is anywhere near the quality of the overlays from the classic days then you will not NEED to use any plexi at all. I have quite a few 15-20+ year old games that don't have plexi and never did and still have stunning overlays. (My Kangaroo, Crystal Castles, Jack the Giantkiller, and Assault all have nearly perfect overlays and never had any plexi on them).
The biggest problem with overlays is abuse (which you shouldn't have to worry about at home), and cracking at the bends, which plexi will not help.
I also reccomend buying a spare overlay now while you can still get new ones. That way in 10 years you can slap a new one on and keep on trucking, but you probably won't need to.