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Following a tip from Mr. Carl Leo I found - then looked closely at the spark-plug water drain holes. As he suggested may happen, my #2 & #3 plug wells were mostly blocked!
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There was debris in the bottom of both wells - and a dried leaf on top still trying to get down there! After cleaning the wells out with compressed air & using a 12ga copper wire as a scraper to reach down in there, I pulled the plugs. I found deposits on the bottom 1/16" of each plug that looked just like the leftovers of boiled-out water. They must have been sitting in water... . But #1 & #4 drain holes were clear & there was very little debris in their wells, and no deposits on the plug bases.
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If you're looking for 'em - the holes to keep clear (compressed air or a fine wire/pipecleaner) are toward the rear of the block right below the small protrusions in the Head casting, if you use a mirror & look up at that area - you'll see the holes that lead to the base of the plug wells.
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Thank you Carl, and to all here who support & contribute to this board & organization. I wouldn't wanta try getting by without 'cha.
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I'm now thinking of cutting that valve-stem off the old inner-tube I've kept in the pile of ... ("crap" my wife calls it) in the corner of my garage - and taking it along as an emergency compressed air tool. Should the need (heavy rain) arise - I'll just use the compresed air at a gas-station and that valve stem to let me blow 'em clear again.