42" center pully grese zerk
 

The thing apparently flew off somewhere. Can I get a replacement off a store shelf or are they specific to the pulley. Do they screw in or pressed in?
Appreciate some input.

You can get a replacement anywhere where they sell grease zerks. A zerk is not specific to a pulley. If it was a pressed in, I'd tap it and make it threaded. Just look in the old hole for threads, nothing difficult here.

Thanks J.
Mike