TZX CSW files

[Mazinfriki]

I'm currently trying to sort my colection of tzx files. I have thousands of them I collected over the years with a lot of files from the same title. Some of them are supposedly different versions from different releases of the same game but I found the data itself is the same, so I am writing a PHP script to help me finding duplicates by computing hashes of the data blocks alone only.

In the process I found I have no tapes with CSW blocks so I can't test my script. Does somebody have any samples?