Damn.... Didn't really want to see a post like yours and sorry to hear about your car.

While my diff isn't showing any obvious symptoms such as creaks or any noises, I guess what happened to you puts everything in perspective.

Budget is tight and may delay driving the car yet alone going to the track but it probably makes sense to replace it even though I think there is a chance that the diff may be fine for a while.

 

There are no unimportant chunks of metal coming off within your diff.