There is a submitted record for 1770 on the IGI giving parents' names as John and Ruth so it might be worth checking. They often have a grain of truth in them! If you click on the batch number at the bottom and put Verrall in the search box there are a lot of entries who might be other family members.
The marriage for John Verrall to Ruth Pierce in 1764 is confirmed by the Sussex Marriage Index and the witnesses were Geo Pierce and Thomas Mantle Verrall.
Andrea