my 420 loader has the steel ones. the previous owner must have hit something hard, because one side was bent pretty good. the steel rod that goes between them was bent up too (still used it as it was for a cpl months). i straightened them both out pretty easily...the rod w/ a press and the bracket w/ a sledge and some steel blocks/wedges inserted in between the sides.
not sure a cast piece would have survived the impact that bent that bracket, let alone be easily repaired. been a few months since i had it apart, but from memory, it's at least 3/16" if not 1/4", thick. i don't think they look THAT bad, but i guess if it doesn't match the cast one, and that's the one you prefer, then it will.
as far as grease fittings, i thought mine had them everywhere that needed them, i'll have to check again and see if there are any on those brackets.