Well, your only pictured Old German Owl is the shield marked bird in Photo #7. Photos #2, #3, #5 and #10 are Chinese Owls. The bird on the right in Photo #2 shows evidence of crossbreeding between a Chinese Owl and another breed (shows a zipper type frill) - the bird on left is a Chinese Owl (same bird in Photo #10, I think). The pair in #3 and #5 are pure Chinese Owls.
Photo #9 (white pair) are probably Miniature American Crests, once a very hard breed to find. They were well promoted in the mid 90's by a breeder in Northern California and were significantly made more common on the West Coast after that. Whites were the most common.
Photo #1 and #4 is some type of crossbred Owl. I'd guess it is two or three generations off the Owl with several generations bred together to get the frill back. The other breed involved is probably a Racing Homer. When I was a kid (a million years ago it seems like), these types of Owl-Homer crosses were fairly common in most backyard flocks.
Same goes for the pair in Photo #6, except it looks like a different Owl cross. The heads show a definite Chinese Owl influence (as does the zipper frill, of course), but possibly some Roller or West of England involvement here. The bird on the left appears to have grouse legs (feathers on feet).
Kind of an interesting batch of birds to me from the standpoint of genetics, but I'm into that sort of thing.