Nickel (Stainless Steel plating) will still have a battery effect. The question is to which extent it will. (Or is the plating Chrome?!?)
Here's one:
http://www.mcnallyinstitute.com/CDweb/g-html/g001.htm
Here are a few more interesting bits of info:
http://www.engineersedge.com/galvanic_capatability.htm
http://rds.yahoo.com/S=2766679/K=gal...alv_series.htm
You can take the baseplate thickness well under 1mm, with the right jet tube configuration.
Drill bits will leave an angle at the bottom of the "dimple", which is undesirable. A square cutting endmill would be much preferable.