Mostly as an aid to other builders, I have posted this a few other places as well - and since I don't think any other source actually covers what you get in each box...here you go:
http://theotherminiaturespage.com/index.php?/topic/1970-pegasus-gothic-city-buildings/I took pictures of both sides of each of the panels, plus the detail sprues (the gargoyles, eagles, knights and all that). I also provided a count for how many of which particular wall panel (or other item) you get in each kit.
I forgot to include a ruler in the pictures though, but to put the dimensions in perspective - the single wall panel is 3 1/4" square. The bricks to fill the holes in the columns are roughly 1/4" x 1/8". So when you see the gargoyle with a little rectangle on it's back - the rectangle is the same size as that brick.