I thought you said one was supposed to be all lop? I would certainly have doubts about anyone who told me that a rabbit with upright ears was a lop. While poor quality Holland Lops may still have some ear control, you won't see that happening in a large breed - the width of the skull and size of the ears makes it impossible. If there is a lop breed in there, I'm thinking it accounts for a lot less than 50% - which will probably work to your favor, since the lop breeds are not specifically bred for efficient meat production. But as long as they are healthy and fertile, "free" is a great price.