Hello Greenvalley,
nothing positive to add, sorry to say, but I did not want you to think that you were being ignored.
Although some census books were lost or damaged, as far as I know all BMDs are complete, subject to the information being recorded in the first place.
Like you, I found no records for Charles Wilson after 1871 or for his sons after the 1881 census. On Jessie's death in 1880, she was recorded as "married to Charles Wilson", and on Georgina's marriage in 1896 she records her father as deceased. This could imply that the informants had some knowledge of his whereabouts.
Jessie has 4 children in very quick succession until 1871. Although there is the possibility of a medical problem, my suspicion is that Charles left the family. His wife's sister (Helen) being informant to her death, and the children being with Helen and their grandfather in 1881 reinforces that view. I can find no sign of Charles or the boys in England or Wales, so Ireland or abroad seem possibilities, unless they changed their surname.
The wording of the will, naming Georgina but making provisions for the other children, suggests that they were not in touch. This may remain a brick wall.
Regards,
John