Thank you for the response. My new batch of shipped Serama has about 50% make it so far and they're from a fellow BYCer, rather than e-Bay. They took 3 days less to get here than the first ones also. They're still a week away from lockdown, but I also purchased a better incubator (fan, egg...
This was the only one with development out of 12 shipped Serama eggs. Is this infection, poor incubation or regular decomposition? It smelled, but not as bad as I thought it would and not until I opened it.