I was going under the assumption that the miss was electrical in
origin because:

(a) the car generally skipped after rain or snow and ...

(b) the skip was rhythmic and felt like it was happening on only
one cylinder

It turns out that I was right. Playing with the wires this evening,
I noticed that two of them felt rather "stretchy" and flexible
where the spark plug boot met the wire itself. Sure enough, when
I ohmed them and wiggled the wire, the resistance varied. Likely,
someone has disconnected the wires by pulling on the cables them
selves rather than the boots causing the internals to separate. I
could have probably fixed this with a soldering iron, but one of the
boots was also ripped, so I decided to get a new set of (Bosch) wires
and plugs. $40 later, the car idles much smoother and doesn't seem
to skip.

So, Art, you were right that the problem might be a broken conductor.
Thanks!

-b.