Those bearings depend upon being greased often and very much. There was a reason farmers used to buy grease in 5 gallon pails, not little tubes....
Basically it is metal on letal, with a big frequently replaced grease film on them.
They look good enough to me as is, bolt together, buy a pail of grease, and use up the grease on them over the next few years.
Perhaps you cleaned them up some, but they should be dripping full of grease, not dry like that!