"..ISABEL" '60s Taxco - hidden mark

[Catfootfog]

I purchased a complex 3D sphere-shaped pendant in the late 1960s of lapis lazuli, malachite and sterling, the hallmark of which is hidden inside the loop through which the chain passes. This makes it almost impossible to see, let alone to photograph.

I can make out a faint "I" followed clearly by "SABEL "
I am 99.9% certain it is "ISABEL" but in strong slanting light there it looks like this is preceded by "M A" or "M B" = "M B ISABEL"??
There are additional marks : "Taxco 925" and "Mexico" forming a circle with what looks like three initials inside this circle, *perhaps* CLL? or GIL?
There is a faint bell-shaped mark with a couple of numbers inside.

Can anyone help ?

Thank you very much.