Thank you sooooo much for your replies.
In the BIVRI-2, I've found the marriage of Diana & Elias and also a marriage of an ELIAS BURBIDGE & JOANNA TUCK at St James's, Trowbridge 9 Jan 1811. Both parties were said to have been previously married. I have a possible christening for Elias 25 Sep 1791 in Melksham, the son of Charles & Jane.
I also found a marriage of a JOANNA SMALL to ROBERT TUCK 2 Oct 1791 in Melksham. I think Joanna may have been christened 9 Aug 1778 in Melksham, daughter of Thomas Small.
If they are the correct Elias & Joanna, there is a possible 13 year age gap or Elias wasn't christened until he was older than an infant. His burial may give his age.
My gg grandmother was JOANNA BURBIDGE, born 29 July 1841, in Melksham to William & Sarah and went on to have a son called Thomas (my grandad).
If I can discover a burial of Diana, it may all fall into place.
In the 1841 census, I found an Elias aged about 40 & Ruth Burbidge aged about 35 in Melksham, so I think they are the Elias & Ruth that Researcher1234 discovered. It helps a lot for elimination purposes. I don't know whose son he was, but no doubt there will be a connection.
Is a printout of the microfiche registers a possibility? I would be very happy to send your expenses etc. If not, it's great to have the info.
What was your ggg grandfather's name, Angela?
Once again, sincere thanks, Shirley.