Very nice work and follow up of your work with pictures that others can easily use to address their slide out gear packs and determine a course of action...
I drop my gear packs once every two years and clean and lube... I also just made an initial measurement on how far out the upper guide rail track gear teeth measured to the outer end on each slide gear pack before dropping to have as a reference point for side to side synchronization of the packs if need be..
In eight years I've not had either of my large hyd slide outs not be in sync with the amount of travel of the upper guide bar...
I would also imagine one could make some measurements and order either some bronze washers to use as shim OR some UHMW washers of the correct ID/OD instead of metal as a shim... if one had the time to wait...
https://www.mcmaster.com/uhmw-polyethylene-washers/