I own 12 pairs of 5As all from IMR... half of them are different. What I mean by different? The crimping on the casing near the positive pole is different.
Noticed this one day when I decided to rewrap a few pair with a gray wrapper to match one of my squonk mods
I immediately looked over mooch's post, contacted IMR, and ran them through my Opus charger to see at least if they got close to the 2600mAh and they did.
When I Pm'd Mooch pictures he was genuinely intrigued about the change, but also said that the 5As were mfg'd in a few different places and its not uncommon to have crimp differences on the cases.
Everything else visually lined up, even weight and length. Performance wise they seem legit. Even in my Tubes running <.12 builds they never got warm ( or abnormally warm )
Visually the crimp on the case looked like the VTC6 on those I noticed, but the mAh wasn't 3000
Long story short...I don't use those 6 in my tubes anymore, and only in my squonks with builds above .25.
Outside of my Opus charger testing the mAh, weighing, measuring and visually looking at the post legs and markings/stamping I am unable to verify with 100% certainty their legitimacy...but I am 95% sure they are legit...plus I ran them pretty hard for months with <.12 builds
Edit: Picture all 5As...left and middle match your pictures of the crimping, right matches Mooch's file photo of the 5A