Dave,
Sorry for the delay. For some reason, I didn't get a brief email telling me that there was a new post in one of my watched Fora.
From top to bottom of your first photo,
Drive Plate
Collet closer set with one probably 3AT but could be 3C collet
Face plate
The drive plate is used to hold the tail of a drive dog which is attached to something mounted between centers.
The collet closer set consists of the handwheel-type draw tube with self centering bearing and the 3MT collect closer adapter. To use, you stick the adapter into the 3MT spindle taper and stick the draw tube through the spindle. You then insert the collet into the adapter and screw it into the internally threaded tube, and draw the collet up until it just touches the adapter taper. You then insert the workpiece into the collet and draw it up snug.
The face plate is used to mount something that is either too large or of irregular shape to the spindle for machining. The collet should have the fractional size that the collet was made to fit engraved or stamped and usually the maker's name,