Yes I did this too and had about 20 backups for every step I made. Then I tested the last version and deleted the rest for saving space. This last version I accidentally have overwritten with a version which was messed up. I also cleaned the recycler before, so no way to get the last good version.

Now I make backups to a USB-thumb also. Don't want to start nearly from scratch once again

So glad that I had the model with all the seperatet surfaces at least, but all the texture work adjusting the maps to the model is lost.