While there is a possibility that some components of the handlebar assembly from a 2003 Honda CBR 250 may fit a 2015 Honda CBR 250, it cannot be guaranteed without further investigation.
Motorcycle manufacturers often make updates and revisions to their models over time, including changes to the design, dimensions, and compatibility of various components. Although the Honda CBR 250 is a consistent model, there may be differences between the 2003 and 2015 versions that could affect the compatibility of the handlebar assembly.
To determine if the handlebar assembly from a 2003 Honda CBR 250 is compatible with a 2015 Honda CBR 250, it is recommended to compare the specific parts and their dimensions, as well as consult the official Honda parts catalog or contact a Honda dealer or authorized service center. They will have access to detailed information and can provide guidance on compatibility and any necessary modifications or additional parts required for the swap.