Jeff
  Not true
  All British autos using Smiths and Jaeger instruments had a squared
O-ring around them as a dash mount buffer.

>
> Date:    Wed, 2 Dec 2009 06:15:35 -0800
> From:    Jeff <vw.doka@GMAIL.COM>
> Subject: Re: Rear heater core valve o-ring source?
>
> That is correct.  The o-ring is round & squared to fit.  Only a
> Vanagon
> could have a square o-ring...
>
> Cheers,=20
>
> Jeff