When you go to polish them check this stuff out. http://www.mothers.com/02_products/05100-05101.htmlGreat looking tank! I've got 3 metaframes to polish up myself, I hope they end up looking as nice as yours.
It's polish intended for cars, but it's about 10$ a jar and lasts forever.
it is a FANTASTIC polish, we use it to polish stuff for car shows. It polishes steel, aluminium and magnesium ( and I'm sure there are others i'm forgetting )