These are the type of batteries i cut my teeth on. Came in a range of capacities from 100Ah to 600Ah
Only after charging the battery can you see if its sulphated. With a fully charged healthy battery the positive plate is a chocolate brown cour and the negative plate is grey.
If it is heavily sulphated charged battery or healthy flat battery, both plates are grey.
The main advantage of glass or clear polycarbonate cases is you can see the amount of material shed from the plates, or "trees" (caused by impurities in the topping up water) bridging plates and causing shorts.
The really large cells were in open topped, wooden boxes, where a dealing stick could be pushed between the plates to remove trees, and individual plates could be cut out and new ones lead welded back in.