Unfortunately the OP has not be around lately - last here about a year ago - but hopefully she will get an email about this thread.
Since 2008 more French genealogy has become available online, much of it through the individual departmental archives. Decazeville is part of the department of Aveyron, and their archives are at:
http://archives.aveyron.frLooking at records from Decazeville, 1833-1842, for example, I see
one under Perry, (Edouard), 11 November 1836
Edouard Perry was the son of Richard Perry, aged 32, from England, and his wife Rebecca aged 31, also from England.
Possibly this same couple had children baptised in Paris in 1833, Richard and Martha.
https://familysearch.org/ark:/61903/1:1:FQK7-NY1https://familysearch.org/ark:/61903/1:1:F73R-99H(Unfortunately a lot of birth records from Paris of this period were destroyed)
They may be the same couple who had a daughter Anne baptised in Bilston in 1828:
https://familysearch.org/ark:/61903/1:1:JQFQ-N38While looking for what happened to the rest of the family, I note that in 1851 Richard is back in England with several of these children (and your Thomas), youngest Sarah b. about 1845, and no Rebecca.
Could this be her burial, in Havre?
https://familysearch.org/ark:/61903/1:1:FQY9-SQ7