Delta Drill Press Belt? Aftermarket Part?

[MrForbes]

you might also consider taking the broken belt to a place that sells lots of them, and see if they have a match in stock.

http://www.bbcarizona.com/

for example. You didn't say how wide it is, so I dont know if there might be other sources.

The urethane belt should be a suitable replacement, if it's the same width and length. The material and "teeth" dont really matter much.