Yes, my station is working, from the older ISS sans solar radiation sensor. Never got to send it back to Davis for refurbishment. The only issue it was having was the pressure sensor drifting. Using the new console took care of that. Will take on the expense of repairing the new ISS as funding becomes more abundant. Since the whole housing is missing, I'm afraid the cost will be the same as a new one.
As far as the Envoy is concerned, it couldn't hurt to take a gander at its innards. You know that something is wrong and that it used to be OK. In most cases, circuit boards are engineered to generous tolerances. When things go awry, it's either a manufacturing defect or the effect of wear. I would imagine that in your case, the Envoy doesn't receive much wear, if any, except in the wiring connecting to externals.
I once had a computer that worked for over a year, just sitting on my desk without being moved. Then it suddenly started acting flaky. It would work for awhile, then it wouldn't. After cooling off a bit, it would start working again. What I discovered was a cold solder joint on the power supply circuit board. Power supply was fine. It just needed to have that one connection re-soldered.
If it's a cold solder joint, then you can't do anything about it (unless it's a large enough circuit board) and even Davis will just toss it. But if a wire has broke, you might be able to fix it or use the knowledge of it to coax Davis into recognizing the issue as a factory defect.
That's just my thoughts on it. Probably not worth much, though.
Been raining here today. Got a 1/4 inch yesterday and 1.1 inch today. I need to eat, go refill the bird feeder, and did I say eat yet?