Ya, I know Bergwerks, or knew of...
I was once thinking of putting shorter gears in my C43. They said they'd done it, and knew the right people (in Germany I think) who could flash the tranni ECU and allow the car to work with the new rpm / speed-in-gear relation so the car wouldn't go into limp-home mode. The only thing that kept me from doing it is they said I couldn't do LSD then too (or they couldn't do it). Dunno if that was because they didn't deal with Kleemann or what, but it stopped me from moving forward.
Anyway, when I was still bidding on 560SLs I started researching 1st gear start, and found Bergwerks was out of business.
Bummer! There was someone on here who I had corresponded with ; didn't have any "in-stock" but stated he might this summer.