When overhauling the master-cylinder assembly, replacing as many of the wear items as possible will simplify the reassembly and subsequent adjustments required to set up the brakes correctly.
Using the correct specification parts is the reliable way to go as well as maintaining a good original appearance.
Other related parts you may wish to view:
Add as many items as you wish to the same shopping cart, a new connector 131591061, switch 270100025 and cap 430261051 for example, and still only pay the same single fixed price shipping cost.
This part may have other applications in the Kawasaki model range - ensure the part-number/s you order are correct for your model?