Directly apply metal spray then after dry spray gloss coat, although the better way would be spray primer > spray metal paint > gloss coat. Make sure don't over spray until thick layer paint for inner frame.

Oh I see, for this you need to check on paint type if it is lacquer, acrylic or enamel. Lacquer paint will dissolve same type and both acrylic or enamel with sequence of lacquer > enamel > acrylic. In your case maybe you could do,

metal spray (lacquer) > marker touch up (enamel) > gloss coat (acrylic or enamel)

With this when touching out detail with enamel paint the lacquer paint won't dissolve and plus point is you also able to wipe off the enamel paint using enamel thinner without screw up the base lacquer paint.