Simpson 260 series 6xlp repair?

Not that I know what a simpson is, but I gather that the suspension has been bent by the glass and that the band is no longer taut.
It requires extreme delicacy to restore these movements, and DIY there's no guarantee that it will be accurate afterwards.
Here is a CA based company that seems to deal with repairs of these meters.

 

I'm sorry but from your description I'm unable to establish a good understanding of how the problem manifests itself..
A wild guess; a metal shaving or a glass shard or some other debris has lodged in the coil/magnet area, stopping the movement at one point.
Another wild guess; the needle or the susension has been bent so that the needle (or the coil) touches something (glass/scale/magnet) as it deflects.
A third wild guess; the pin in the adjustment screw does not align with the slot in the adjustment fork - maybe it's bending the fork instead.

 

Once you have the glass in place, when you place the meter into the glass holding cover, make sure that the pin that extends from the adjustment screw aligns with the center of the U shaped slot on the movement adjuster. That pin may be on the side and you moved it one way, but now have no means to move it back. When it is in the center of the slot, the pin will move it left and right. If that U was bent back, you may have to carefully bend to back towards the glass.