Yes, thank you for the pics.
It's really the typical defect membrane gluing. The space between the frame and the membrne has to be accurate filled with the water proof white glue as mentioned earlier in the treat.
See the attached picture...
It's difficult to say. This because the rattle can be caused by other reasons too.
Those reasons are:
- Dust in the magnetic air gap - mostly caused by old and defect foam particles from the foam in the center or the wooden box-package.
- Insufficient wire loop - wires could touch the membrane while moving
Of course it could be also not sufficient glue.
To analyse it help to vary amplifier gain and check if the rattle is constant there or it just start from a certain loundness onwards. If this is true than it's not likely that it's still the membrane glue the cause for the problem. Because the poor membrane glue effect rattle almost at any sound pressure level.
Hope I could help!