As I'm sure you know, Death was a common surname in Suffolk, so your Thomas could have baptised in many places, even if he lived in Baylham at the time of his marriage. I checked on familysearch.org and found quite a few Thomas Death baptisms, but the most likely to be relevant was this one at Claydon, which is not far from Baylham:
Thomas Death, son of John and Susan, was baptised at Claydon 25 July 1749.
Worth pursuing at least a little further, I would think.