I think I have found the Devonshire connection!!!
Firstly
William Solomon (who at this point looks likeley to be Richard's father) is unmarried and working as a farm servant in 1851
however
1861 shows him married to Elizth and the eldest child is Susan age 11
I could not find a Susan Solomon born c. 1850
Then I found this!
1851
St Ewe Cornwall
Richard Devonshire head 49 Ag lab St Ewe
Mary wife 52 Werryau??
ELIZ daughter 25U Farm employ Gorran
Caroline daughter 15 Gorran
Emma daughter 10 Gorran
SUSAN daughter 1 St Ewe
HO107 1908 31 4
didn't think it very likely that Mary Devonshire age 52 would have a 1year old daughter -so possibly the daughter was the child of Eliz
then
Marriage
Sept qtr 1852
on same page
Elizabeth Devonshire
William Solomon
5c 197
so it looks very likely that Richard could be
Richard Devonshire Solomon mar qtr 1853 St Austell!!!!





??
Suz