Looks good Paul. The decals are normally applied to a smooth, glossy surface to avoid 'silvering' etc, and this is what a gloss clear coat is used for. This is followed, after the decals, by another clear coat, to give an even appearance, then the required clear finishing coat - matt, gloss, or semi matt or whatever. However, on a bare metal model, I normally apply the decals to the paint, then give them a coat of clear, only immediately over the decals, to seal them. This then leaves the metal as .... metal! You can apply a clear coat overall, but be aware it will alter the appearance of the finsih, the choice is yours.