A gearbox overhaul would not be completely satisfactory without replacing all of the worn and/or damaged components. Leaving an old, partly worn component in one area of the assembly will prematurely wear out those nice new parts that interfaces with it; not an ideal outcome!
Other parts related to the transmission assembly you may wish to consider:
Add as many items as you wish to the same shopping cart, a new nut 9017922018 and oil-seal 9310240330 for example, and still only pay the same single fixed price shipping cost.
Pro-workshop gasket sealant, 08C70K0234M for a professional results standard.
Please be aware that this component may have other applications in the Yamaha model range. It is always worth double checking the parts-numbers you order are correct for your model?