Hoyt Epic were limbs weren’t they? Not a riser. Or the Epik which was a riser but takes the current grip system. Do you have a pic of the riser? Everything since the Helix/Nexus/GMX takes the new grip (mid 2000s). Avalon, Elan, Aerotec, Matrix (Axis kind of) , later series GM, take the “Avalon” grip. For the later your looking at eBay or an old shop stock (or very expensive boutique custom grips)
HTH
Stretch