An Anglo-Italian 3-inch naval gun project

In the Fleet of Oceans timeline, why would the Royal Navy not simply adopt the Italian 3-inch naval gun?

The likelier arrangement is a joint project, with OTO Melara and a British firm producing national versions of the shared design.

In the Fleet of Oceans alternate timeline, the Royal Navy still develops a 3-inch gun rather than simply adopting the Italian weapon unchanged. The likely outcome is a joint Anglo-Italian project, with OTO Melara producing the Italian version and a British firm such as Vickers or BAE producing the domestic counterpart. National production lines would therefore sit inside a collaborative design effort. This is a counterfactual procurement judgment rather than a claim about the historical gun's actual origin.