Ok, so I pulled out all of my Karachi amps and gave them all a good look. It turns out that the fill level varies a bit from amp to amp. I think it is due to inconsistencies in glass shape. When I first looked at it, it looked like the 2/2014 were filled higher (because the few that I looked at WERE at a higher level... less than 10% difference.. you can see in my picture). But when I looked over all of them, I noticed that they all vary a bit a far as fill height regardless of date. All of them have a little glass 'nipple' on the top where I guess extra glass accumulates and solidifies. The liquid is the same color in all.
But the fill height is deceptive, because it still could be the same volume of liquid, just in a differently shaped vial. And the vial variability is the question in the first place, ie why are some of them taller than the others? So I decided to do a little experiment. Besides, shooting a couple extra amps cant possibly HURT my cycle...
So I took the fullest looking amp and the lowest level amp and pulled each into a separate syringe. I removed the dead space pushing the oil to the end of the needle on each. Here are the results: full looking amp: 1.1 cc. low-level amp 1.05 cc. So what appeared to be a very large difference in fill level turned out to be almost the same amount of liquid. Conclusion: these amps vary in diameter, height, and shape (volume). They could be legit, we are unsure, but my leaning is still that I think they may be OK.
Does this sound reasonable? Anyone know anything else that I should know?
Thanks again!