John, you did not look far enough.  I have those O-rings in stock from VW.  From my <www.frankcondell.com/sales.htm>  webpage: O-ring, crank pulley, 2.1 w/power steering, N 900 784 01 - 8.86    They are necessary, without it there there will be leaking.  Just had an engine in here that had been leaking for some time.  Turns out the engine had recently been rebuilt by "someone" and they did not install this O-ring.  Why ?  No one knows.

On 2012-10-23, at 8:14 PM, Automatic digest processor <LISTSERV@GERRY.VANAGON.COM> wrote:

> Got an oil leak on my 2.1 coming from under the pulley. Might be the oil
> pump, but I suspect a seal There is/was a large diameter "O" ring seal
> and a smaller seal - and the large "O" ring is for those engine with P/S
> and A/C. It seems this "O" ring is NLA. At least I cannot find any
> vendors that have it. Van-Cafe shows it on their website but they
> haven't been able to get it for some time.
> 
> Question is - is this large "O"ring necessary or is the smaller seal by
> itself sufficient to do the job. I have never had this apart before so
> am not quite sure what I will face when I tear into it, but I sure would
> like to have the correct and necessary parts on hand before I start.

Cheers,    

Frank Condelli
Almonte, Ontario, Canada
'87 VW Westy, '00 Kawasaki 250 Sherpa, "98 Ducati 750 Monster & Lionel Trains (Collection for sale)
Frank Condelli & Associates - Vanagon/Vanagon Westfalia Service in the Ottawa Valley
Vanagon Stainless Steel Exhaust Systems
BusFusion a VW Camper camping event, Almonte, ON, June 06 ~ 09, 2013