Until the repro gets remade (if EVER), that topper is HTF and way expensive if that.
Apparently "planking" is an issue however I've never been able to figure out why one machine over another would succumb to this as what I've learned from my industry is it's usually humidity related.
Inserts however, as mine displayed a little, may not have been installed 100% or adhesive used may have been or become wonky - check for insert level & separation.
Shooter lane - all the force from balls going up and coming back down from soft plunges are taken out in a small area which accelerates wear.
Yup, cracked ramps, if not cracked and heavily yellowed - they are also becoming brittle.
Boulders near pops - usually get cracked from airballs - make custom (if someone hasn't produced yet) clear protectors. If cracked they can be repaired using epoxy and painted. When painting use over a light desk or light source so transparency is maintained.
Great game. Miss mine, less some of the sound fx.
-Rod