It would work but this is a very old combination for Co-browse, almost 3 years old. The current version of Co-browse is 8.1. Also, at this time, Co-browse is offered only as a Cloud product. So, the customers will be using the 8.1 version. There might be multiple integration issues that might crop up due to this integration of 8.1 Co-browse with such an old version of Pega CS. Is there are compelling reason why you would want to do this? We recommend atleast upgrading to Pega CS 7.4. The integration there is much easier and mostly Pega Express driven.