I have used the diaphragm and gaskets pictured. I haven't used Greg's yet but after reading this thread will be contacting him soon for some other projects I need parts for.
I am not sure if it was something I did wrong, but when I used these parts my phonograph doesn't play very loud. The clarity and range sound OK, but there isn't much volume. The diaphragm isn't very high quality. It appears to be made from the same cardboard that is used by clothing stores for gift boxes. It is laminated but is really pretty cheap material. So all in all, I would go with the advice to use Greg's. I know I will be contacting him soon.
Hope this helped!