Hello all!

I am replacing a head gasket right now and am about to reinstall.
My gasket kit was short 1 "O-ring gasket "  (Bentley Page 15.22).
Desperate to not lose more time waiting for a replacement, I talked to a local VW mechanic who hadnt worked on a wasserboxer in a long time, but said that he couldnt remember the O_Ring, just the flat metal ring.
It is clearly there in the bentley, and says "always replace".

On the other hand, I tore down a blown 1.9 that I had lying around today, and there were no O-Ring gaskets installed in there, and that van had NO water leaks at all.

Questions:

1. Do I really need the O-Ring gasket?

2. Opinions on whether to put sealant on both sides of the new head gasket... The 1.9 that I took apart today only had sealant on the head side, not on the case side. (Again, that engine had no leaks)

Thanks Alot,

Jason L.
85GL 2.1