M.K.
Usually I'm about as frugal as they come, but when it comes to the safety of an infant, I would definitely trash this one since it's so old.
I would take out all the straps and hardware, even go as far as breaking off pieces, if you can, and take it directly to a recycle center. Or you could put it in a black trash bag (so no one can see what it is and be tempted to grab it), and put it out on pickup day.
Good luck!!