Not many real AH-1G kits were made in 1/72 scale. There are later AH-1 Cobras but just Monogram and Matchbox did the early G model. The Monogram kit is the better of the two. It is an initial variant with the tail rotor on the port (left) side of the boom.
The old Matchbox AH-1G kit is a later variant with the tail rotor on the starboard side. It is probably easier to find than the Monogram one since it was re-released in a Matchbox box after Revell of Germany ended up with the molds. The Matchbox one has decals for both a US Army Cobra and one of the initial 38 AH-1Gs given to the Marines. The decal quality of the Revell reissue of the Matchbox kit are superior to the decals that come with the original Matchbox issue. Same markings, just better quality decals.