Closet door

This closet door continues to come off the track due to age, wear and tear. As you can see from the photos, the track is pretty beaten up. I'm not sure about the rollers, so I included photos of them. It is in my daughter's room and I'd like to keep it if I can for cost reasons. There is a crack in the mirror which is at the bottom and not very obvious. What would you suggest I do for replacement parts? The closet is 72 x 80 and the Stanley label is on the back of the mirror, which is how I found your website. This is a quality product and I doubt either Lowes or Home Depot would offer a decent replacement. Plus I'd like to save some money.