Most GTB EMs of the 70's and Classic Sterns all have them as well under slings, behind drop target banks and in in the outlanes neat the aprons. The GTB ones are nails but the Classic Sterns are straight metal pins.
If they are too high and rubbing on plastics, you can always tap them down slightly to lower them. They aren't there to hold up plastics, but to rather keep balls from getting trapped behind the rubber rings in the spaces between the star posts.