Andrew,

Just a guess based on you description.  I think your valves has a
deposit built up on the face from normal combustion.  Usually  slightly
brown in color.  IO think that some of this build up has chipped off.
Not a problem since you are going to clean the rest off if you re-use
the valves.

I concur with the suggestion that you take the heads to a automotive
machine shop.

Walt

>-----Original Message-----
>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>Andrew Martin
>Sent: Tuesday, September 23, 2008 11:32 AM
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: resealing heads - found missing metal on top of valves
>
>Since I cannot post photos here...
>
>http://www.thesamba.com/vw/forum/viewtopic.php?p=3307618#3307618
>
>Thanks,
>
>Andrew
>
>
>