STEP files are today available from many sources, especially because all major mechanical CAD systems are supporting STEP. We list here only a few sites with STEP files. If you want us to add further links please let us know.
AP203/214 test files
AP210 test files:
Others:
If you know other web-sites with public available STEP models that you would like to see listed here please tell us at info@lksoft.com