This is a very old building set and probably from the 60's or so considering its complexity.  I don't remember this one at all but Transogram was big in that time period.

 The girders and parts are made of plastic and the loose ones in the lower part of the box are crumbling.  Literally, you can rub them in your fingers and have them break down into dust.

In the bags the parts are in better condition but there are some broken pieces among everything.  I would think that even the better pieces would be as fragile so this is one to display instead of try to set up and play with.

There are little tiny used rivets (look like screws) in one of the bags but the toy rivet gun is missing.

The box is there but has been flattened and is extremely dirty.