The pictures are not clear - but the two up top look to be cast brass buttons (they have heavy ground action or corosion) the one on the bottom looks to be a piece of melted lead or led/zinc mixture. Scratch it with a knife and see what color is underneath. The buttons were most likely civilian flats, and by the thickness and (what appears to have been an attachment for the loop) early 1800s - though that is just speculation as they are again unclear in the picture and no backmark present (though the one at the top right appears to have had one - most likely an old english BEST PLATED