1841 HO 107/1464/5 ES35 p.33 dist 2a
Malew St, Castletown, Malew
Patrick Maxwell, 27, Hawker, born Ireland
in household of
Mary King, 42, labourer
with Catherine Wallace, 27, FS
Patrick Mc Kenna, 58, Mat? Maker
3 labourers from Ireland
2 men from England
4 yr old girl from IOM

1841 HO 107/1464/8 ES21 p.8 dist 2a
College St, Ramsey, Maughold
Sicilia Maxwell, 25, born Ireland
Michael, 7, IOM
Ann, 4, IOM
Susannah, 1mth, IOM

1851 HO 107/2524 f.339 p.23 sch.100
College St, Ramsey, Maughold
Patrick Maxwell, H, m, 38, Hawker of ~~, Ireland
Cecilia, w, m, 37, IOM, Castletown
Michael, s, 16, Tailors app., Douglas
Ann, d, 14, Castletown
Susan, d, 11, Ramsey
Patrick, s, 7, Ramsey
Edward, s, 5, Ramsey
Cecilia, d, 3, Ramsey
Hannah, d, 6m, Ramsey

1861 RG9/4429 f.72 p.22 sch.129
College St, Ramsey, Maughold
Patrick Maxwell, H, m, 47, Rag dealer, Belfast, Ireland
Selah, w, m, 46, IOM, Castletown
Patrick, s, un, 17, shoe maker, Ramsey
Edward, s, 15, Ramsey
Selah, d, 11, Ramsey
Hannah, d, 8, Ramsey
Margaret, d, 6, Ramsey
Sarah, d, 4, Ramsey

1871 RG10/5773 f.166 p.16 sch.90 dist 3b [Ancestry indexed as Mascwell]
19 College St, Ramsey, Maughold
Patrick Maxwell, H, m, 60, General dealer, Ireland
Cealer, w, m, 60, Castletown
Sarah, d, un, 15, servant Genl, Ramsey
Cealer [“ditto”?], boarder, ~~7, England
Sarah Senescal, boarder, 4, England
Eleanor Collins, boarder, 80, IOM Castletown

Cecilia was obviously an unusual name at the time and hard to spell. Suggest look in wife's birthplace, Castletown, for marriage, or Ramsey, where they seem to have had a long term home.