A strung harp is under a tremendous amount of tension. The wood on an antique harp may not be in any condition to bear this tension. There may be internal damage or warping that is not immediately evident. Stringing the harp at all may cause it to snap. Leave it unstrung until you have had it assessed by a professional.
Once the harp has been determined to be structurally sound, appropriate stringing depends on the model of harp. String tension on harps made before the mid-20th century was substantially lighter than that of current pedal harps (closer to that of most folk/Celtic harps). On the majority of our antiques, we use modern lever harp gut and specially made wires from Vermont Strings. However, there are exceptions which need lighter stringing or which can handle heavier stringing. Take a look at our Strings and String Tension page for more information, or give us a call to discuss.
PLEASE NOTE that modern standard pedal harp strings require much higher tension than your antique can withstand. The harp may crumple if you put modern strings on it!