AutoCad :: Electronic Versions Of Some Older Drawings

I've been tasked with creating electronic versions of some older AutoCAD drawings for which only hard copies exist. There are a lot of them, so in an effort to expedite the process I thought I would try to scan the drawings and scale them appropriately so that I could just go through and trace the lines. I was planning on doing some sanity-checks of the measurements in the AutoCAD and actual drawings as well. This would save me the time of having to measure the length and angle between each of the lines on the drawing (to which there are wild variations) before drawing them in AutoCAD.

The problem is that these drawings were printed on some really large paper (Ex: 4ft by 6ft), so I can't really use a desktop scanner. My thought was that I could mount the drawings on a wall and take photographs of them using my camera instead. I would use the photographs to trace lines in AutoCAD.