My Elizabeth's brothers were Edward, b 1821 and died in Bolougne-sur-Mur in 1888; Charles, b 1824 and died at sea (unknown date); and Henry, b 1827 and died in Oxford UK (date unkown.
Edouard could be the son of any of these brothers, but Henry is the "best fit" at this stage, who would of been 28 in 1855, and who went to the UK where your Edouard was recorded in the 1871 census in Greenwich aged about 16.
However, "Edouard" could be the French version of "Edward", and it is equally likely that Edward, born 1821 (who would be aged 34 in 1855) could be the father. It may be possible that the young Edouard went with his uncle Henry to the UK to further his studies. However, as you point out, there is strong circumstancial evidence there is a connection between our Muntons. Please let me know what your research reveals and we can then possibly connect all the dots.