Be that as it may, the church was closed when I was there so I was unable to see inside, but here's a good sampling of the heraldic stones that I found alongside the church while I was there.
As you can see from many of these pictures, they have placed a protective fence in front of the memorials. That's good for the memorials, but tougher on the photographer trying to get a clean shot of them.
The following three photographs are of the helm and crest, coat of arms, and inscription, respectively, of the stone above.
Finally, these last two pictures are of stones set into a brick wall at the back of the car park, and not along the exterior wall of St. Mathias church.