There are some casualty records for JG 200 but this name is not among the ones I have. However I do have evidence that there were other losses from the unit for which names are lacking.
I also have some pilots' names from 1. and 2./JG 200 as remembered by
Uffz. Walter Lang. The nearest to Eyerer is "Fehrer". Lang did not always remember names correctly though.
I am sorry I can't help more because this unit interests me a lot.