Ray, thanks for the Marriage Licence info. its nice to have confirmation that that Thomas was from Botesdale.
The burial info fits fairly well with his obituary printed in the Bury and Norwich Post - Wednesday 07 August 1805, which reads as follows
"On Monday last died, in his 63rd year, after a long and severe affliction, supported with truly Christian fortitude and resignation, Mr Thomas Slapp, attorney at law at Botesdale. A gentleman of the strictest integrity in his profession, universally known, and as universally respected. His social disposition, and the natural warmth of his feelings, rendered him a most agreeable companion, and a most faithful friend. In the nearer relations of life, the excellence of his principles, and the many good qualities of his heart, renders this event most sincerely and deservedly lamented, and will stamp his memory with the most sacred and lasting regret."
His baptism should be 1742 to 1744 and I hope in Redgrave or Botesdale (his residence is variously given as "Redgrave", "Redgrave cum Botesdale", or "Botesdale".