Yep. They had both the hinge that goes between the two panes and the "flap" that goes on the back one. Both pieces just just slide on. They even the little handle to attach to the one that lifts up. (my 75g tank has one of these hinged set ups on each end...so 4 panes of glass, and a fixed piece of glass right in the center that the 2 end units rest on)
is not a chain, but it is a pretty big operation. Definitely more than a mom and pop shop. They have all sorts of peices and parts you can buy, but they are not out on display. I usually just take in a broken part and ask about it and they get me what I need.