True Vintage Silk Dress 1950'60's? Small

This was in my grandmother's attic, not sure of the age. The only flaw I can find is a bit of fade on each side of bottom of the skirting, which is not too noticable with all the color/design on the dress. Priced to sell for a reseller, or someone who collects vintage clothing. I have seen something similar on Etsy go for 500. + Needs a cleaning.otherwise in nice condition.