
One possibility....
Could Edwin have been married? He joined the Royal Navy in 1870.
There is this marriage:
3rd Qrt 1866
Edwin W CLARK
Portsea
Vol. 2b/ Pg. 642
Two possible brides: Elizabeth Thorn and Maria A Humby
Edwin would have been young at the time of this marriage, c. 19.
Of course, this marriage needs confirmation to make sure that it is the correct Edwin.
If correct, first wife could well have died before 1877 when he married again in 1877. Although, didn't the register show him as a bachelor? Need to double check that.
Could go a long way to explaining the various aliases I would suggest...
Monica