Sensei 72-77mm Aluminum Step-Up Ring

Is it possible to find one (even at more cost) not made in China?

You will actually need a step down ring- this particular ring will enable you to use 77mm filters on a 72mm lens. The correct item you need is the Sensei 77mm-72mm step-down ring: http://bhpho.to/1sDgEm6

I'm sorry, no.

Yes, you can stack 2 filters with the same size thread but beware of vignetting (darkening of the edges) with wider angle lenses.

They are about 5mm thick which is about the same as a standard UV filter ring.

Yes, the black color and finish covers the entire step up ring.

The Sensei 67-95mm Aluminum Step-Up Ring has course 1.0 pitch threading on the 95mm side, and standard 0.75 pitch on the 67mm side. This is fairly standard for these sizes.

If your filter/attachment is larger than your lens, it's a step-up. In this case, your fisheye attachment is 37mm and your lens' front diameter is 30mm, hence, you'd need a step-up ring.