Are you sure that the vendor is really B & S ?
AFAIK B&S do not retail directly they wholesale to their dealers who retail to the public.
As for buying off Amazon / Ebay
have said it 1,000 times but no one seems to listen.
A 10 year old can set up an ebay/amazon shop that looks like they are a long times experienced major dealer the flog off trash they have bought as scrap metal.
In 7 years as a technican who buys from real aftermarket companies ( Stens, Rotary Prime Line & Oregan ) the only things that have caused me grief were;-
Fuel taps that had neoprene seals, a 25 pack replaced without question
Honda gear change springs that broke, again replaced without charge ( slight delay on them )
Chain Saw bar with lamellar fracturing, the batch was recalled & replaced
And that is for around $ 300,000 worth of parts
Why people play parts roulette on ebay & Amazon for the sake of a few dollars is some what beyond belief.