I had the same thing with my Galaxian, although the original leathered T-molding of that one looked much more like the "current" version and not as "rought" as your original.
Is that Joust-2 a US built machine or Euro (wonder if there ever were Euro Joust 2's, I don't really think so). My (Euro) Joust seems to have the same leathered T-molding as your original.
Maybe the molds have just worn out after 25 years ?
Try KLOV forum, probably more chance on a good answer there. I doubt there will be any alternatives.....
Sometimes, you have to compromize a bit....