The biggest thing with alclad is to first know that it is NOT as hard as people think it is!
Second is to have an absolutely perfect smooth finish for the paint.
Spray it up in light coats (round 12-15 psi) untill you get the look you want.
Here is a link to the NMF GB I did, my Hun is a few posts down.
cs.finescale.com/…/154399.aspx
I did not use different tones of alclad, just gloss black base. Then did about 3-4 light coats to get a dark allu look. Masked off a few panels and did 3 more coats to lighten the rest.
A claercoat of alclad semi matt used to seal it all.
I usually spray lacure thinners to clean the brush, then a cup of turpentine to lubricate the neede before I put it away.
Theuns