That's an excellent suggestion and I had thought of it, but in my "morning after" stupor I neglected to note the registration of the plane. But surely it would somehow be possible to find out what plane operated the MIA-DUS AB7001 flight on 9th February?
I paid with the Payback AMEX card, but having called them there is no Versicherung despite having used that card to purchase the glasses. In the UK you are pretty well protected in such cases if you use a credit card to purchases items such as new spectacles.