There are no model specifications for Article 120 (2012), but if there were then they would probably be these model specifications
Congress amended Article 120 in the FY12 NDAA, with the new statute taking effect on 28 June 2012. That date passed without any Presidential rulemaking to list elements, define terms, provide model specifications, or establish maximum punishments (the things usually found in Part IV of the MCM).
But a few months later the JSC published a huge proposal of changes to the MCM, including the Part IV materials for the new 120 offenses. Unfortunately, when the President finally signed the next Executive Order, he defined only the maximum punishments.
Because of this, today there are still no official model specifications (a.k.a. sample specifications) for Article 120, Article 120b, or Article 120c. But we do still have the JSC proposal including model specifications that, while not formally adopted (yet), are the next best thing.
So, working from the JSC proposal (as published in the Federal Register), I pulled out the proposed Part IV for Articles 120, 120b, and 120c, cleaned up the formatting, and saved it as a single Word document available here (link).
The file includes the elements, explanation, max punishments, and model specifications for each of the 44 ways of charging Article 120, the 17 ways of charging Article 120b, and the 6 ways of charging Article 120c.