Models of Concurrency (MoCs) are formalisms used to capture the concurrent aspects of complex systems. They provide powerful abstractions to model and reason about concurrency, that are mapped to the underlying execution platform's facilities. In this paper, we extend the existing GEMOC concurrent executable metamodeling approach enabling the specification of Concurrency-aware eXecutable Domain-Specific Modeling Languages (xDSMLs) to ease the definition of new MoCs. This approach relies on dedicated metalanguages to separate the data concerns from the concurrency ones in the operational semantics. The latter are captured as CCSL models which define Event Structures, enabling their use for concurrency-aware analyses, refinements and variations. However, this elementary MoC is not the best fit for all concurrency paradigms; and extending the approach with additional ones is complex and costly. We propose a solution to seamlessly define and integrate new MoCs through a recur-sive definition of concurrency-aware xDSMLs, enabling the use of a previously-defined xDSML as a MoC. This allows a complete tailoring of the MoC to the xDSML, facilitating the debugging of the MoC use by relying on the execution facilities made available for free by the concurrency-aware approach, and paving the way for additional analyses depending on the xDSML used as MoC. We illustrate our approach on fUML and show our implementation in an Eclipse-based language workbench, the GEMOC Studio.