I hate to bring this old thread back to life, but I used the advise here to order a shell plate to load 7.5x55 Swiss on my Dillon 650. Found this thread via Google search.
I ordered the L shell plate and #4 buttons. I have some once fired Prvi 7.5x55 brass I want to load, but they were not even close to fitting in the L shell plate. I called Dillon and they are replacing it with a C shell plate. I will let you know how that one works out.