Hi BB,
For what its worth... I was told by a German auto mechanic here in So. Cal. that DMF typically are not machinable without completely being dissembled, machined, and rebuilt with new everything. He said it was more cost effective to purchase a new one. This fellow is from Germany and has been a Merc, BMW, Porsche mechanic most of his 60+ years.
So unless the machine shop there in NY has a really effective way of assuring the flywheel is locked down and doesn't move or they rebuilt the whole thing I'd almost suspect the flywheel as being warped or as mentioned the clutch disc is wrong or is compromised somehow. As far as being backwards it's pretty hard to put one that has a dome on it in backwards. I would think you would notice it as soon as you attempted to install the pressure plate. I've only done one so I'm not an expert but just some thoughts...
Good luck, Cheers