Left to right
The gold eagle is an honorable discharge lapel pin which was for wearing on the label of a civilian suit coat. When one was discharged a similar, but cloth, patch was sewed over the right pocket to indicate that the soldier had been discharged and not subject to orders. Very few soldiers had civilian clothes to wear home after discharge and the patch indicated to MPs and such that the individual was no longer in service but was wearing the uniform while returning home. Honorable Discharge Lapel Pin
The black cross is not a medal, it is a marksman qualification badge and worn beneath the ribbons of awarded medals. Badges are noted here
Not sure what the ribbon you have is for, it does not match ribbons issued during the war that I can find, see obsolete ribbon here
As far as devices to be worn on medals/ribbons. If your grandfather had five awards, the ribbon itself is the first and the devices to be attached to the ribbon make up additional awards, So, if you have four stars then, four stars plus the ribbon makes five awards. Had he six awards, then he’d have the ribbon and a single silver star to indicate six awards. For example, on my father’s Pacific Campaign ribbon he wore the ribbon with a silver star centered with two bronze stars on each side of the silver – 2+5+2+the ribbon = participation in 10 recognized campaigns
