Y888

I dont think aftermarket are available,i havent seen it on the internet.
Right now cheapest pump assembly with gasket is 890$ from audi delaer in arizona(last one)on ebay.
It has to be done right to avoid future problems.

Hatterasman

I purchased just the pump and the seal kit pictured in post #15. Way cheaper than buying the full pump and bucket. Requires a little time and patience to remove the pump from the bucket and replace it, but will save you a ton of money. If I recall correctly the replacement pump I got was made by VDO and came from England.

Running out of fuel at 1/2 a tank may be from improper re-installation of the bucket. The pump has to make a 3/4 turn, while held at an angle in order to engage to fitting that pulls fuel from the "other side" of the saddle tank. Google a DIY on the pump and you should find info on this...it's VERY easy to get this wrong.