Dwarves and the northern war of the rings

[Dain]

From the appendix to RotK:

Years afterwards Thror, now old, poor and desperate, gave to his son Thrain the one great treasure he still possessed, the last of the Seven Rings and then went away...

Even had he had it, the ring couldn't have been removed from his cold, dead hands, as he was killed in Moria and mutilated and fed to the crows.

But the possessors of the ring did not display it or speak of it, and they seldom surrendered it until near death, so that others did not know for certain whence it was bestowed. Some thought it had remained...in the secret tombs of the kings...but...the kindred of Durin Heir believed (wrongly) that Thror had worn it when he rashly returned there.

So, they don't know where it is, and only the closest to Thror would really know he had it. It was the first of the Seven.

Though [dwarves] could be slain or borken, they could not be reduced to shadows enslaved to another will; and for the same reason their lives were not affected by any ring, to live either longer or shorter because of it.

So, there's another question. Sorry about all the quotes now, I just thought I'd insert some textual evidence to back up what I was saying.

The John Howe picture is very cool. I don't think Dwarven rings--like the elven ones--turned their wearer invisible. That was just a convenient power of the one--not that it worked on Sauron. I wonder if Tolkien regretted that at all...