Have located the parish register for the marriage of Thomas Holden and Anne Young on Ancestry -
http://interactive.ancestry.co.uk/16...-00184/1893321
Appears they both signed their names.
Working from that, and given that St Marylebone and Uxbridge are just 16 miles or 6 hours walk from each other, and this make the two locations very plausible for job relocation within a 15 year time frame...
There is a baptism at St Marylebone in November of 1780 of a Thomas Holden, son of Thomas and Ann -
https://familysearch.org/ark:/61903/1:1:JMNR-G5L
baptism register on Ancestry indicates his full name was Thomas Senior Holden
http://interactive.ancestry.co.uk/16...0_194664-00077
Senior as a middle name when one is an infant seems unusual to me
After that, the next baptism I can locate for a child of a Thomas and Ann is one for a James Janson Holden in 1793 in St Marylebone -
https://familysearch.org/ark:/61903/1:1:JWZP-PXX and
http://interactive.ancestry.co.uk/16...1-00375/530493
Then we get into the ones I've already located in Uxbridge.
IF the 1780 born Thomas is of the same family as the 1798 born Thomas, then I can only presume that either the 1798 born Thomas has the middle name of Junior, or the 1780 born Thomas died prior to 1798.
If Thomas Holden and Ann Young are my kin, and their children's birth/baptism years are 1780, 1793, 1795, 1797, 1798, 1800, 1803 & 1806 - then I wonder what happened between 1780 and 1793.
Haven't yet got any further on the burials mentioned, that's for another day.