>>5861931I think the earlier HK figures are the ones that flake more, ie Bronze, Gold, Steel. I believe the later figures like the HK originals have better paint, but I've seen some of those flake as well so be advised. If you do buy one ask the seller for pictures of the parts to see if there's any damage. Pic related is the armor for a Marine Cloth that I have so you can see how bad it can get.
>>5862067I already knew those were bootlegs when I bought them since I'm collecting those as well. Most of the original Bandai ones I got were from Japan, so if you buy from there you shouldn't worry. For boxed figures, the engrish text is a dead giveaway. Every bootleg I've seen also has all copyright and logos removed from the box and figure. All official figures (except the 2000 Italian reissues) say Bandai on the bottom of the feet, so if its missing that chances are its a bootleg. Plastic quality isn't the best indicator since even Bandai's own plastic varied from figure to figure. The best indicator I think is the paint application and excess flash. I have a few bootlegs with great quality plastic, but literally every one I have has sloppy paint and lots of flash and excess plastic. Missing paint apps or incorrect colors are another good sign. IIRC, the St. Fighter V2 Dragon had armor that was lighter than the original Bandai one.