In contractual systems engineering projects, the developing organization is often required to demonstrate compliance of the system's requirements against a myriad of engineering standards and government regulations. In order to satisfy this goal, the project requirements imposed by standards and regulations through the contract need to be traceable to/fro appropriate project artefacts (such as the contract, various system and sub-system requirements specifications, standards, regulatory documents, etc.). However, these artefacts form a complex interrelationship network, leading to significant challenges in demonstrating requirements compliance. Current practices dealing with such compliance are ad hoc and arduous. In this paper, we identify key artefacts, relationships and challenges that we are currently discovering from a case study on a large-scale, contractual, requirements compliance project. These findings can be a basis for creating a meta-model for requirements compliance in a systems engineering project. This paper describes the on-going case study, the emerging findings, and their implication.