The dense foam backing on my 1990 WMS Funhouse STEP targets had worn out.
Like other standup targets with foam backing, the foam causes the target to
act almost as a rubber post on the re-bound. Any local hardware sells dense
foam weatherstrip for use around windows and doors. Pull off all the old
foam and cut a rectangular piece to fit. The stuff comes with adhesive on
one side is a no brainer to apply. It's also great on the inside of the
lock down bar that holds the playfield glass in place.