Not too sure about that, right at the crown on the casing you can see a little bit of copper at the crimping area, which actually means the solution could not plate there because it was sealed with a glue or clear sealant.

I know what you are describing, but in THIS case seems to be ok..
i plated two different threads once and realized they should have been connected, now they dont thread.. need a good brass brush to fix that i think, but this looks decent..

the tank was cold when i did this and some are cloudy, i was just doing it as an initial experiment. hopefully they fire.. i will find out eventually..