...my mistake. I thought they also came with the manual movement, but I see from the Nomos site that they are automatic only.
Regarding Grand Seiko manuals, the limited edition SBGW003 model (quite beautiful - see Steve G's launchpad) comes with a display back. 300 pieces, I think, but they come up from time to time. The big Japanese ADs that ship to the States might still have one, for all I know.
[Whoops, just looked up the SBGW003 - it's 36 mm diameter.]
good luck, Tom