The Spot A and The Spot B still listed on the priority post box finder https://www.royalmail.com/services-near-you#/results?postcode=DE1%202HR&latitude=52.918802&longitude=-1.475191&searchRadius=40&count=7&filters=&officeType=postboxes

Have checked on the ground and can see the rough surface on the pavement where the two pillar boxes were

Don't think that they we will returned as they are very near the main post office https://www.openstreetmap.org/node/3530542504  https://www.openstreetmap.org/way/129320971