89 with 84,000 miles. Sits most of the time. Clutch started feeling spongy. Sometimes it just won't work, then it starts working again. Doesn't matter if it is cold or warm. Seems to not work more often when in reverse. If I add fluid, do I have to bleed it?

 

You probably have questionable seals in your master and/or slave cylinder. I'd start with replacing the slave down on the transmission since it's subject to more weather and grime.