Global Scale Modeller

I have now some metal parts painted.

This being the engine with dark iron tone and guns and exhaust gunmetal, and what i think is a radiator painted aluminium.

So my question is what varnish finish should i apply?

normallly metal is gloss varnished, but for example for the engine, exhaunt and guns should it be gloss or satin?

for the aluminium im thinking about applying gloss.

this for a BF 104 E3 what you guys think or usually do?

(on the exhaust i will apply rust pigments later)

ok so i have been thinking.

normally guns and stuff have this sheen not quite glossy.

so all dark metal parts i will varnish satin, the alluminium i will do it gloss.