After closer inspection, some scratches were still noticeable on the tank. And more obvious when lights are on.
So change of plans - to get a new tank instead. The current tank has been reserved by a bro who will re purpose it as a terrarium. I'm damn keen to see when that's done up.
Other updates
The original sump was quite simple (left & right compartment). Inspired after seeing some nice sump designs done by Iwarna & another from LCF425's tank, it would be nice to add some compartments in the sump for filter wool, bubble trap etc. Glass is hard to work with. Acrylic is easier for DIY but bonding acrylic to glass may be an issue.
Did some checking up & found that using a structural adhesive to bond glass-acrylic is possible.
Dow Corning 795 is a RTV (Room Temperature Vulcanization) structural adhesive & does not use acetate accelerators (i.e. does not smell of vinegar). Because it cures 'naturally', it takes 2 weeks to fully cure. A check with the distributor showed this is supposed to be one grade higher than regular sealants.
Pic of the additional panels inserted. They hold up very well.