Val,
Frederick's age and place of birth seem to bounce around a bit:
1901 Census (10 Dock Parade, Newport, Monmouth)
Frederick Baker; age 70; Coal Shipper; b Hastings, Sussex
Mary Baker; age 58; b Newport, Monmouth
Interestingly, they have a 10 year old daughter living with them
1891 Census (23 Castle St; St Woolos, Newport, Mons)
Frederick Baker; age 57; Labourer at dock; b Sussex
Mary Baker; age 49; b Newport, Mons
1881 Census (23 Castle St, St Woolos, Newport, Mons)
Frederick Baker; age 46; Coal Shipper; b Hastings, Sussex
Mary Baker; age 35; b Newport, Mons
1871 Census (23 Castle St; St Woolos, Newport, Mons)
Frederick Baker; age 37; Labourer; b Hastings, Sussex
Mary Baker; age 27; b Hastings, Sussex
1861 Census (4 Canal Parade, St Woolos, Newport, Mons)
Frederick Baker; age 27; Coal Shipper; b Newport Mons
Margaret Baker; age 26; b Bristol?
1851 Census (Marshfield, Newport, Mons)
Frederick Baker; age 17; Farm Servant; b Newport Mons
There are no good candidates in the 1841 Census for England. Perhaps Frederick was already in Wales by that time.
As for marriages, there were the following marriages for Frederick Baker in Monmouthshire:
Dec Q 1854; Newport District; 11a, 308
Margaret Coleman
Jan Q 1871; Newport District; 11a, 215
Mary Ann Thomas
There is a death registered for Margaret Baker in Dec Q 1868 in Newport District (11a, 106).
I hope that this is helpful.
Regards
Mark