Packaging Guide:

• The 'Diaclone' Box simply has a metalised type sticker of swoop with blue chest on the counterfeit box.

Figure Guide:

• Color variants: Normal Red Chest, 'Diaclone' Blue Chest, Gold Wings Version
• The diaclone blue chest version has additional differences such as the pointed beak, gold dinosaur feet, gold chrome sword etc
• Blue chest version also has the takara(Japan) manufacturer stamp on one wing and Hasbro on the other. (Real diaclones just has the one wing stamped).
• Counterfeit has the takara(Japan) manufacturer stamp on one wing and Hasbro on the other. (Just because a swoop has both wings stamped does not make it a KO - it just rules out single wing stamped swoops and macau swoops from being KOs).
• Here are some helpful differences (These have mostly been resolved on later runs):
• Factory applied stickers are not applied. They come on a sticker sheet instead, same for the rubsign.
• Toy itself is relatively low quality. Soft plastic was used, the toy doesn't fit together well, and it's generally loose.
• The red paint on the diecast chips very easily.
• Initial figures had unpainted heads. Subsequent runs included an extra painted head in the package that can be swapped out with the unpainted head. 
• Some of the initial run comes with Grimlock's sword instead of Swoop's sword and the launchers were ill fitting in the wings.
• Swoop has never been officially been reissued, any Swoop being called a reissue is likely a counterfeit.

The below photos were saved from AC Toys before the links were broken. Many thanks to the original creator.