Rear sprocket bearing

I was rebuilding the rear chain sprocket on a 1972 750 after years of neglect.
I found the 4203 bearing had surface spalling on several of the balls. I checked another parts sprocket and found similar damage to the bearing.
Is this the typical failure of these bearings?

What is the latest advice on bearing type replacement? I see that new 4203 bearings are around $43.

I've pulled these double-row bearings a few times and they are rough ...I figure because of neglect and lack of periodic greasings. It's kind of hidden in the hub and previous owners probably didn't even know it was there to grease. Recently there are sealed double-row equivalents available to fit , Walridge motors sold me mine along with sealed wheel bearings.