I'm hoping you are still up to date with this site as your msg is a few yrs old now!
I have ancestors with the surname Alder.My furthest at present is a Robert Alder b.1809 in Newcastle I think.He married (in Alnwick) a Margaret Bell Stamp b.1833 from Alnwick and they had 6 children that I know of; Thomas Stamp Alder 1833-1903, Robert William Alder 1838-?, Mary Ann Alder 1840-? (middle name is also Elizabeth on some census records), Elenor Canor Alder 1843-1889 (my GGGrandmother), Edward Samuel 1845-?, Harriet Alder 1848-?, and Ralph Thomas Alder 1850-?.
Do any of these names relate to your family History? I look forward to hopefully hearing back from you.