[Tony Van Helden]

I checked again doing the buble test, for the proverbial air leaks and so far nothing obvious.
I went down the road, as mentioned above, as a result of the short cycles rather than the "leak down" to the 80 lbs trigger.  That seemed like some sort of a valve malfunction.  The compressor runs about 1/3rd as long as it used to.  This started, actually, after using the auto level.  I've since quit using that.  Not sure if it's related or not.