There are companies that can make new lenses using old ones as a pattern, even broken ones that need repair first. Year ago, when I bought my 65 Cuda, it failed inspection because the PO put blue dots in the rear lenses. They looked to be silicon'd on so I popped them off. There was a hole in each lens under the blue dots, which also failed inspection and that red lens repair tape fails too, I asked. Back then no one was reproducing those lenses and an good NOS pair was almost 25% of what I paid for the Cuda. Permatex made a repair kit that was clear epoxy, with a packet of red dye and amber dye. I also had some tools/molds in it to fix the lens. Worked good, still there 25 years later and you still can't tell. Unfortunately, I can't find it anymore.