Glaze has been removed after improper cleaning, how can I get my veneers re-glazed without removal?

These cements are made up of resins and with time tend to changes shade. so suppose yr doctor use same type and brand of cement after few years there r chances of shade difference. 

Best and only ideal option in your case is braces / aligner treatment. but if u r not ready for that thn u can go for crowns . but its my advice to choose braces treatment.

 Your lower teeth  are too crowded for veneers,  you would get a much better and healthier result with Invisalign or orthodontics.   Veneers could be an option after straightening your teeth.   You would be able to retain much more of your healthy tooth...