My recent Yamaha stuff has come from https://www.bhg-marine.co.uk/
Their stock, price and service has all been good.
The other thing is - is it really a Yamaha? I'm not familiar with that motor, but certainly my Yamaha is the same as a Mariner of the same vintage, and my Evinrude 5hp is the same as a Suzuki. Makes sourcing some parts easier.