Software Product Line engineering aims at reusing and automating software development to reduce costs, have shorter development cycles, and maintain quality. However, for organizations with settled development processes and a large code base, adopting an SPL approach may prove to be a daunting task. In this paper we present an industrial experimentation and a proposal for an SPL adoption in Heinsohn Business Technology (HBT), a software development company specialized in financial, transportation, mortgage-backed securities, and pension-fund solutions. We start by identifying and modeling multiple levels of variability inherent to the kind of developments undertaken by HBT. Next, we define restrictions inside every level as well as between the levels to fully characterize an HBT software product. To limit the impact on the organization development process, we use an extractive approach. This allows us to design core assets starting from current software artifacts. The overall approach is based on real-world software artifacts developed over the years by HBT, whose combinations result in approximately 4.88e11 possible product configurations.