What you have is a tank built by an old time tank builder. He is building tanks using old school methods. He is snapping the glass and then grinding the edges so they don't slice a finger.
Modern tank builders, building in higher production numbers, use cnc glass cutters and water jetting to cut the glass. They then polish and chamfer the edges. This makes for a much more finished look - a mirrored edge to the glass what the heck out 90 degree edges.
Cutting the edges down by chamferring the edges make the glass less likely to fracture if hit on the edge by something with some mass.
While this may not be the most "finished" of aquariums, or cleanest built, structurally there is nothing wrong with the integrity of this aquarium and it should hold water safely for decades.
If these raw exposed edges are an eye sore to you, you could tape off the visually exposed edges and then basically caulk with black silicone and then use a smooth wet edge to slide along the caulking and leave your self with a clean black edge to the glass.
This will not make the tank any better as far as integrity but if the appearance bothers you, it will make it more appealing.
Dave B
