yet another type 44 A/C conversion opportunity

[hah at srv.net]

Haudi, 

(a quick Tab & space bar combo sent previous message a little early, wups)

This weekend's warm weather prompted me to turn on the A/C in my '91 200q, 
to no apparent effect. CC diagnostics indicate low-pressure switch is the 
cause, I'm guessing the compressor front seal because it's been oily-wet 
on the compressor bottom front for a while and I don't seem to be losing 
Pento$in CHF 11S from the pump up above.

Therefore:
A) Will a local A/C repair shop tend to be equipped to service the front 
seal - any other seals in the compressor need replacing for R-134a use? 
ISTR someone posting about practicing front-seal replacement on a similar 
compressor recently...

OR

B) Anyone got a part number (Nippondenso, right?) and/or source for a 
rebuilt R-134a-compatible unit? I will have to get dirty at some point to 
take it off there, but there's no point to getting dirty right now if 
someone has a P/N handy. James has a set of gauges and we will probably go 
in together on a vacuum source and big can o R-134a for his 200 as well. 
Some FUD in the archives regarding GM cross-platform compatibility, and 
ISTR some funky manifold box attached to the compressor that's supposedly a 
special Audi thing...

OR

C) Sanden/other rotary compressor, anyone? People keep talking about this, 
anyone done it yet?

We are all having good luck with R-134a conversions other than compressor 
seal issues? I am in Boise, Idaho so it does get warm for a couple of 
months but not Arizona/Texas hot-hot-hot A/C all-year-round.

TIA
Henry Harper
http://www.srv.net/~hah
1991 200 quattro, 112k, gas hog around town and dead A/C too
1988 GTI 16v, 217k, fuel-sipper and ice-cold R12 air ever since I got it