If your enamel will take seven days to cure and you overcoat it with another varnish (discounting the compatibility issues) how is the enamel going to cure?
Paints cure by evaporating the solvents to the atmosphere (simplified argument). If you seal the enamel under another coating it cannot cure, so will stay soft.
I think the fact you have already put a gloss finish on your model removes the need to put on the Klear coat.
Just my interpretation, not an expert view!
