The word "once" does a lot of work here, because when someone went looking for it in April 2018, it was simply gone.

The slab was documented by Bradley and Dunne in 1992, who placed it in the west wall of the church at Abbeyland. Medieval graveslabs of this period are typically flat, carved stones laid over or set into a structure to mark a burial, often bearing decorative or inscribed detail. Whether this one bore a name, a cross, or any ornamental work is not recorded. What is recorded is that it was there in 1992, catalogued and noted, and that by 2018 it could not be found on physical inspection. It had not been formally reported as moved or removed; it had simply ceased to be locatable.