and now for the finished product:




To get the "silver" scratch effect - I did an old technique that I use for armour models.
I first painted the unit in silver. After a day of drying,
I filled up my airbrush with the floor polish called "Future".
After drying, it makes a very good seal of the paint underneath. (warm water for washup).
It usually does not react to the different paints I used - but you should test it first if your not sure. (makes a fine bubbly mess if you guess wrong)
After that - I painted it black, let it dry, then with my trusty knife, I scraped off the black, not too deep, to show the silver.
the future makes it easy to just remove the black - leaving the silver untouched.
after that - a few coats of "dull coat" (testors) and it's done.
Thanks again to ss for his tutorial - and to Hyperdyne labs for the electronics package that powers it up.