Thanks, Don. You confirmed my suspicion that between closed throttle and WOT, there's a broad 'normal zone.' So even if my TPS isn't clicking like Jiminy Cricket it's not affecting normal part-throttle running.

I tried a spare filter I had on hand, but the rascal kept leaking on the supply end (in spite of new copper washers). During the "enhanced tightening" procedure I managed to put a pinhole in the stamped hex on the filter, so the clogged fuel filter has not been ruled out yet. Heading out to pick up a new one and will try again shortly.

However - any thoughts on how to check for a plugged cat, without removing it?