Beyer could source some of the parts elsewhere and still say they're made in Germany. I think you're right though, the Taskars are copies. According to many, they did a damn good job. The 2050 and their Pro 80 each have 53mm drivers. Is that unique?
I was thinking of getting a Thunderpants kit for my T50. Those wood cups are so beautiful, but I decided to DIY cause I didn't even know at first if I would like them. Stock T50 is all midrange with lousy bass and rolled off top. They also have a break-in in excess of 20 hrs. It's disappointing when you can't figure out if break-in is done; when you check they still have lousy bass etc.

I read through some of the mods on Head Fi and paid particular attention to Thunderpants and that long thread. All it takes is some modeling clay, a tiny bit of speaker Dacron (Acousta Stuff) and a pr of 840 pads. I didn't use damping sheets inside the cup. They'll reduce the volume of the enclosure. Instead I used clay on the outside to make a ducted port. There are pictures somewhere around here, probably a page or 2 back. There's just a couple of things you have to look out for. There's a tiny vent hole on the driver mounting near the top of the driver. That has to be left open. If I remember correctly the 840 pads have foam in the middle. I cut that away for better treble. The internal 3.5mm jack tends to get loose and lose connection. Gently squeeze the contacts on top of the plastic housing with a needle nose, and it's easily fixed.
Fostex says the efficiency is 98dB/mW @ 50 ohms. It seems like less. Those cans will take some power. I get the feeling, if I hook it up to my 50 wpc tube amp, it wouldn't be too much. They have a relaxed kind of effortless sound. Really glad I got them.
neo