Getrag 5-speed /85 W123 300Dt

[seo]

Hi,
I have two W123 sedans, one a wrecked '84 Euro grey market, NA engine, 5 speed Getrag, crank windows, tow hitch, etc. Before the car was wrecked I had done the job of replacing the clutch (broken pressure plate spring), and had had to search for the correct parts.
The other one is a U.S. market '85 turbo sedan with Otto matic trans & turbo.
Question 1) I asked the local driveline builder how they'd address getting the engine balance right, and they said that if I brought both the flexplate/torque converter and the Flywheel and clutch assembly, that they just balance the flywheel assembly to match the flexplate assembly, and that would work. It sounds logical. Does this make sense? The company:
www.butler-macmaster.com/
has a good reputation around here.

Question 2) The transmission nameplate reads: Original Mercedes Benz
Teil Nr: 123 260 2001
Aggregat Nr. /80 024716 (the "7" may be a "Z")

Before the car got wrecked, the transmission was making a funny "clanking" noise only while in neutral with the clutch ENGAGED. It sounds kind of like a bad throw out bearing, except that with the clutch engaged the bearing isn't turning... I've been told that the problem is something about a shaft that runs in a bored bushing in the aluminum case, and that the fix is to bore it out and install a bearing.
Is anyone familiar with this gearbox or this problem?
Are parts available? either from Mercedes or Getrag?
Can anyone recommend a transmission guy who's familiar with these?
My plan is to take the car off the road this winter, and I wouldn't be in a screeching hurry to turn the job around.

Question #3: I hate the U.S. car's "not so Smart" climate control, and have toyed with transplanting the manual rig out of the Euro car. I've been warned that this involves tearing the whole dashboard out, and is a pain in the neck. Anyone done it?

Thanks for any advice.