If you do know of a book, and you can order it, I would advice to order it, even if it takes a long time to arrive.
Romansh is such a small language, and therefore Romansh given names and their meanings such a very narrow topic that I doubt that somebody will be able to provide such a list.
Romansh is officially the "4th national language of Switzerland", but if I look at the numbers, and the actual importance, that strikes me as something like a joke. As I see it, it is kept alive mostly for political reasons, with lots of money and effort, like a rare type of animal that would be long extinct if not some zoos were carefully breeding it.
But still, I agree that Romansh given names are an interesting topic, just very difficult to find information about them...