I checked a compression test that was done on the van a year and a bit ago.
 It had a reading of 60/115/120/140.  If I read that right (those readings
are for 1/2/3/4 cylinders) then the one that was stuck on is #1.  Perhaps I
did not break that piston ring after all?  (also, presuming that cylinder
#1 is the one closest to passenger in north america)

I'm also wondering if I should disturb the valves at all.  It seems like a
logical thing to approach while I am in there, although I'm not clear on
how much benefit would be gained vs the extra work and chance of messing it
up.  I realize I'll need a spring tool if I take them apart.  A new set of
valves and guides seems to be around $100 - and in my novice mind, new
valves would seem to be important for compression.  I've done quite a bit
of googling but can't find much on valve maintenance, bar the adjustment
and nosiy lifter discussions.

My current plan is clean it up as best I can, install all the new gaskets,
and then back together.  Once I clean it then it'll be more apparent if I
can get away with that or not.

Tom
84 1.9L