I'm not 100 % convinced that the France-born Henry is the right fellow. I know it all fits with age and occupation, but on the 1851*, the last column for afflictions such as deaf/dumb/blind is ticked off for both Henry and (presumably his older brother) James.
On the 1871 census for Henry Mantle born France, it indicates the affliction as number "1", which the column header indicates as "deaf and dumb".
All the later censuses that are your Henry "for sure" have no affliction indicated. On the 1911, there is lines drawn through that column indication no afflictions, so at least on that one, it wasn't an oversight of not filling out all info.
*Edit: corrected typo for year of census