Rolex ~1940's Vintage Oyster Precision Ladies Rolex~

Manual wind, ladies Vintage Rolex in decent shape. Still works and very hard to find. It does have the authentic hologram, serial number etc.. Had it confirmed as a genuine Rolex at Edmonton Jewelers and was offered $800 for it. Unfamiliar with rolex i thought it was worth 5 times that and refused the sale. The strap is not an authentic Rolex strap which sucks but the time piece itself is a genuine rare ladies Rolex. I'm asking $550 for it but am open to reasonable offers.