Now I try to harness the vast power of the internet think-web.

I'm trying to find out the author and title of a story I read once, years and years ago. I think I might have read it in F&SF, but won't swear to it. The story's about a sort of halfway house for people who have strange abilities. Some of the characters include a man who can repair any broken machinery, but after he fixes them, the machines have strange properties; for instance, he fixes a car, and the first time it makes a turn, it disappears into another dimension. There's also a woman who can see angels (or at least one particular angel), and though no one else can see her supernatural companion, there's little doubt that it's real. There's a creature that takes on physical and personal attributes that are pleasing to an observer -- for example, coming to resemble a widower's dead wife. I think there's also an older man who goes around the world repairing rips in the fabric of reality, and I seem to recall a phrase about there being "lightning in his hands," or something similar. It's possible the lightning-hands guy is from another story altogether, though!

Anyway, I've been thinking about this story off-and-on for years, and it would be nice to be able to read it again. I'm sure it must be in the library at work somewhere, and I can track it down if I can find out the title and author. My google skills are not up to the task of finding something with such vague parameters. Does my description ring any bells?