Greg I don't have Casa in my collection, and never have. I have had it in my 'Want List' for quite some time.
It would not be correct to rename it 'Casa 2', as it is already a hybrid that we just don't know the name of, so wouldn't be right to give it yet another name.
We are working closely with the nurseries to correct errors, they are as interested in proper ID as we are. SMG is checking on this one right now. Don is very good at doing this. As is Cynda and Toby. All strong supporters of having things correct. We are so fortunate to have them.
The bonus to buying from reputable nurseries is that they will correct the error and replace an incorrect plant. This is not just a business for these nurseries, it is a passionate love of sempervivum.
It is always a good thing that we can have dialogue while clearing up errors. This is a great way for us to come to solutions.