The two are very similar and, without seeing the hidwing (which has additional characters), I felt more comfortable with the forewing markings being those of C. neogama.
You could always try asking the CNC.
These two species are extremely similar and there is no way to be certain. There are plenty of photos that are "mislabelled". People interpret differences based on these labelled images, many of which may not be under the right heading. So right now, they are best identified by specimen analysis.