My 1997 Celica is back up and running! I replaced the timing belt for the 2nd time, and thought it prudent to replace the water pump and timing belt tensioner and spring and the bearing for the idler pulley. There was a sizeable oil leak that I concluded was from the front main oil seal and replacing that required replacing the crankshaft sprocket, since the old one would not come off without being drilled and tapped for use of a frogfoot gear puller. I also removed the lower oil pan and replaced the RTV seal.
And of course one of the bolts holding the wheel liner snapped off during disassembly, so I had to drill it out and retap it.
When I first cranked it up this morning it squeeked very loudly. Turned out that all the belts were too loose, even thought I had gotten them pretty tight. I tightened the belts and now it sounds fine and runs good.
Based on this experience I think I'll just walk everywhere.