Avoiding G dupe filter

We created an excellent .co.uk cloaked site with loads of pages - (if I may say so myself!)

The client saw it high in the serps & then said "Oh, I wanted a .com to appear as our audience is mainly US"

So.... we've also done a .com which I'm not happy about.

Theres 400 cloaked pages on both sites.
Every .com page is 20%+ different to the original .co.uk page yet theres no sign of the .com on the serps.

Both are newish domains but I don't want to kill the .co.uk while its the only one ranking high.

How can I differentiate the .com enuf that it also shows?
Thx a million
J

PS - Help via sticky might be preferable depending on your thoughts?

On 2 cloaked sites