Thanks, that is what threw me, I thought it was Penallt, but then as you say FindMyPast had it as Bishton.
It is a bit of a coincidence that the Thomas Chadwell who died in 1797 died in February as did the Thomas who died in 1917 Lydart said the date is quite clear on the tomb, otherwise I would have suggested, given the style of tomb, that it is that of the earlier one.