Mark Plastics
I have an 85 28.5 and did this 2 years ago. The plastic trim you refer to is no longer available anywhere.I touched base with Mark Plastics. Mark agreed to tool up to make these frames since it was a common model.Mine fit perfectly. Mark should be able to take care of this for you if he's still in business.Mark Plastics369 East Harrison StreetUnit G.Corona, Ca 92879909-735-7705