local bearing shop had some 303345 equivalents for my 9.5hp MQ for $11 cdn but they are steel so I coated all exposed outside surfaces with 2 coats of contact cement to seal them from water
inside will be in oil so I was not worried
IF they give out after a few years i’ll be edging on going out myself
Certain I have missed many (sorry for that): Ken Hall, EdE, Dan Gano, Chris_P, Pine Lake Parts, Ferguson Poole, Big Rich. We are really fortunate to be able to obtain parts for 60+ year old motors. Also some of the suppliers on eBay are members do not fail to look there too.
Others PLEASE jump in with the many other good suppliers I do not know.