Almost last night...stay up till 6 this morning (I know you've done that Terry! ) and slept till about 11... then my parents dragged my tired self out of the house to go out to lunch.
If a silver or metalic paint is of the same kind like the rest of paints you are going to use , it has to be applied at the end.The reason for that is that the thinner in a paint attempers the foregoing layer of the silver ( metalic) paint. Also it makes these aluminium and silever ones getting darker. So you have to use either a different kind of silver ( aluminium ) paint as the previous layer ( an oil enamel if you use acrylic paints for instance) or apply it as the last one. Just for the future.
Of course you could have applied the white paint on the model and then masked these areas.