1986 4000S, Brake questions

[Peter Biernacki <pbiernac@ea.oac.uci.edu>]

The car in question is a manual 1986 4000S with a 1.8L 4 cylinder
engine (7/85 production date).  Front brakes are disc, rear are drums.

Front Brakes:
I am about to replace the front pads and rotors on my car and I have a few
questions in reference to the Bentley repair manual.

Page 46.1a indicates Rubber-coated silencer shims P/N 811 615 231

However no Audi dealer in my area can find these.  Does anyone know of an
updated part number or what the deal is?  I already have a set of pads,
new mounting bolts and some anti-squeak paste.  Anything else I need to
replace when doing the job?

Rear Brakes:
These definitely need changing too.  I also know that the wheel cylinders
are leaking a bit.  My understanding is that I will need new brake
linings and brake wheel cylinders.  Do I also need brake drums?  Anything
else?  Finally, the Bentley manual makes mention of "G6 grease", does
anyone know what it is and where I can get some?

Any advice is greatly appreciated,

Peter