Well i've spent a frustrating hour looking through my files trying to find my source on John and Mary's marriage and the only one I have is Boyd's Marriage Index which doesnt' have that level of detail
I have over 600 sources in my database and can't believe I didn't record this one, but nothing turned up in a google search either, so I'm going to have to chock it up to a data entry mistake on my part.
I have the marriage date as 15 Oct 1804 and the witnesses were Thomas and Ann Bonfield, which leads me to believe someone emailed me the info but I can't for the life of me remember who or when
The name Moyses turns up in the Cambridgeshire baptism index as Moises and occasionally Moyser, and I was able to find that John and Mary had four children together, the last being Alice in 1812, who died a few years later in 1826. After Mary died in 1820, John married Ann Springfield in 1821 (per Boyd's index) so yes, that Ann Moyses burial you found in 1830 was John's wife. John and Ann had three children together.
There is a burial record for a John Moyses in Thorney Abbey in 1829 which is only four miles from Whittlesey so it could be him.
Thanks for your time. I appreciate it :-) if I come across my source for the mysterious info on John and Mary's marriage I'll post it here.
Cheers
-Claire