I do know that our sliding glass door is a pella door installed at the same time these windows were.

Looks like you need new windows, you will not get an air tight/ energy efficient window by only making repairs. I can understand preserving a window that is over 100 years old and it has historical significance, but other than that, you need a replacement.

A few more pictures would be helpful. If the windows are Pella like the door there might be a service tech that could come out and look at them for repairs if possible. If they fall that means the sash balance needs to be replaced, as far as the gap more pictures would help in understanding the problem.

If the door is Pella, chances are very good that windows are as well.

Ill take more pics tonight and post em...thanks guys

wide shot of the window for Identification

here is another close up of the drop

I found the balancers..just not sure how to get at em. These are the springs for the upper sash closeup.,I forgot to get a pic of the gap..but it is uniform across the top..like the springs are toast.