A number of approaches for spanning the requirements-architecture gap have been published in recent years, and we sought to rigorously characterize the gap and to conduct a comparative evaluation of approaches to span the gap using a case study method on a realistic problem.  However, our intentions were impeded by the problem of finding appropriate subject systems that included sufficient information in both requirements and architecture document.  Most subject systems that we found contained either detailed requirements or detailed architecture description, but not both.  In this paper, we report on our search and the seventeen most suitable subject systems with the hope of aiding others undertaking a similar study.  We speculate on the reasons for the paucity of suitable subject systems and invite contributions and suggestions for our ongoing work.