The best this I can suggest is to contact Prof. Roger Kitching at Griffith University - he is also on Researchgate. He is a good entomologist, I am not.
Rudolf Felder was an Austrian lepidopterologist. According to Dr. Martin Loedl, natural history museum of Vienna (Austria), the coillection of Rudolf Felder is deposited in London. So you will find the types there. Maybe there are also slides of the genitalia.