Jean Bart would need a uniform main battery

Could Jean Bart be completed with a mixture of British 14- and 15-inch guns?

Probably not; any refit would favor one uniform main battery because a split caliber makes ranging and fire control a nightmare.

Jean Bart would receive a uniform main battery if rearmed. The proposed mixture of British calibers is rejected because it would make targeting difficult. The answer does not settle which uniform battery she would receive.