I too have been looking for list of released settler captives taken pre 1760.Yes every once in a while I see a small list (6) but know there is a larger list naming the children released at Fort Pitt to Bouquet for one.1760-1765 ap.
In the Colonial Records PN Archives Vol 8 page 628 I did find this list. Return of English Children, delivered up by the Indians and Canadians, that were taken in the Province of PN and Colony of VA;Nicholas Silvias of Plow park in PN. taken in 1755 by Indians.; John Mann of Marsh Creek in PA taken in 1758 by Indians.; Frederick Payer of Low Bergenin PA taken in 1756 His father killed but his Mother he believes is still living.; Anne Coon of PA her Mother dead and her Father was taken at the same time.; Isaac Toople taken near presque Isle in 1756.; Mary Williams, da to one Daniel Williams, taken by Indians on the Delaware about 5 years ago; Believes her father and mother were killed.; Peter Underwood, taken about Winchester; belongs to VA.; James Curtis, Upon examination appears to belong to the Mohawk River and therefore is not sent.1761 dated.
There are other list with in the Colonial Records but will take time to search them out.There is at first printing at least 16 vols.
I wish there was a "heading" for those interested in the French Indian Wars.... and released people...