Hi Ruskie,
There's a reference on LINC Tasmania Names database for a Daniel Wilkins departing on the 'William Melville', 30 Mar 1850 from Launceston to California. Could this be your fellow seeking to make his fortune in the gold rush in America? Ship he came on is referred to as the 'Manfield'. Though looking at the online image it could be 'Manford'. No evidence that he returned to Tasmania but might be worth investigating.
https://linctas.ent.sirsidynix.net.au/client/en_AU/names/search/results?qu=Daniel&qu=WilkinsAnne Wilkins (nee Richards) appears to have remarried the year after Daniels death in 1877 to William Wallace Noakes -
https://stors.tas.gov.au/RGD37-1-37p255j2k She died at Ulverstone in 1895. Note informant was a brother, Frederick Richards -
https://stors.tas.gov.au/RGD35-1-64p192j2kHer death notice in the 'Daily Telegraph', 5 June 1895 -
DEATHS.
NOAKE.— On the 4th of June, at her resi-
dence, Ulverstone, Ann, wife of William
W. Noake, and eldest daughter of the
late John and Jane Richards, aged 59 years.
In a Golden Wedding Anniversary notice from 1914 a Sarah Richards is noted to be marrying Henry Crocker in Launceston, 24 Sept 1867. Parents John and Jane Richards are noted as living in Cameron Street. A Jane Richards died at Cameron Street, 23 June 1887 aged 64 -
https://stors.tas.gov.au/RGD35-1-56p22j2kA John Richards died at Cameron Street, 24 Jan 1889 aged 76 -
https://stors.tas.gov.au/RGD35-1-58p4j2kThere is a Maurice Richards signing as witness to Ann Richards second marriage in 1878 and there was a Morriss Richards born to a John Richards and Jane James ux Richards in Launceston in 1841 -
https://stors.tas.gov.au/RGD33-1-23-p676j2kThat leads you back to a marriage in Hobart in 1835 between John Richards and Jane James -
https://stors.tas.gov.au/RGD36-1-2p186j2kHope that might give you some leads...
Cheers,
Peter