I don't think you can consider them gay. They're only gay by the standards of our homophobic society. That type of person could only be described as bi (I'm not bi, but it just seems like only bisexuals would be into that), because a gay man is not just attracted to genitalia, but also to the male body and form. for a gay man to be attracted to a pre-op transwoman, would not make much sense....just because they have a penis, doesn't mean they are attractive to a gay man. If she is not attractive to you with clothes on (as a woman) , how is she any more attractive to you with a penis.