The Mag "A" (metal) riser didn't have a top and bottom quiver mount holes. Perhaps a hole was drilled later, or sometimes the medallion was removed and that hole was used for the quiver. There is also a small hole just above the grip for access to the side plate adjustment screw.
A picture of the riser will be a big help.
The Kodiak bow quivers( long with two bolt brackets) are reversable. I have one-new in the box.
I will be away from the computer until Monday.