Well, I had a few back-and-forth emails with Jensen at Durst-Pro-USA. Because this is for students, he very generously offered to send a used, but good condition replacement TRA500 at little more than shipping cost. I am still interested in fixing this device, but now it is not as urgent as before. I think I will look at replacing just the board components that are damaged.
I can't thank Jensen enough for his help getting this up and running. The link you provided for the capacitor is great. Once I get the replacement, I should be able to identify exactly what went in that spot.