[Vwdiesel] headless EuroVan - rings/valve cover ooze?

[rOLf peCHUkas]

hey all
question for diesel-heads:
how tough is it to do rings on a headless engine on the side of the 
road?
I figure I'll have a nice tight head going back on this thing, maybe 
let's do rings while we're at it,
doesn't feel like there's any ridge at all, just a slightly 
rougher/more carbony lip top 1/4" of the cylinder walls
anyone know which way the pistons come out? up out of the head if I 
release the con rod(s)?

also:
there is a flying-saucer-shaped black disc coming up out of the valve 
cover that leaks a thick black ooze down the valve cover and onto the 
injectors
(slow and almost a solid, but still an unpleasant gunk I'd rather not 
suffer)
it is an air-related mechanism - connected back to the intake filter, I 
think
any idea what this is/what it does/how to stop it from leaking?

thanks again

Rolf
Side of the Road, Leverett, MA