Tim, your dismantling the Elan the right way. Photograph everything! I just ordered a replacement wiring harness from British Wiring for the Elan S4 I am restoring, it is very well made and color coded to the manufacturer specifications. The S1 harness is much simpler, you shouldn't have any problems.
Pay attention to the shims (sometimes they are washers) used between the chassis and the body as well as the shims under the steering rack. The exact location and number of them is vital!