So - the ONLY reason the washer finally turned up, and worked beautifully when I replaced it in the supply line valve, is because I'm probably going to have to cut off that whole valve and put a new pressure valve on the line. Some blankety-blank fool soldered the nut holding hard water supply line in place. All it needed was finger tightening, not solder, fercrhristsake. I'd probably break the fitting before I was able to twist off that nut.

The fastest way to find the thing that is misplaced? Buy another one - the first one turns up the moment you enter the house with the new item. Never fails.