GMC horn button and center caps

[Todd68Chevy]

I picked up some loose parts when buying another parts truck last weekend and wondering what a couple items are worth before trying to sell them.

First is a GMC horn button. I think it is a 68. Very minor pitting and the rubber ring has some weathercracking where the square is-- see picture.

Second is a set of 4 center caps. I do not know what they are off of. The guy thought they attached to a full hub cap. They are a heavy metal. Decent shape but do have some fading, pitting and paint missing. I would call them good driver condition. Any information on what year they are and/ or what they are worth would be helpfull.

Thanks for your time and information.