Good morning Sage
I'm absolutely thrilled my hunch re - Janet Hamilton & Robert Crawford paid off!
Like you, I was very aware that the couple marrying in 1858 could have been an entirely different Robert and Janet .
But it looks like Robert married Janet in Nov 1858 then after her death married her younger sister Elizabeth in Dec 1863.
And it's probable that Robert and Janet had at least 1 child -Thomas Hamilton Crawford who died as a baby.
Bearing in mind that the daughters with his second wife are named following the traditional 'Scottish naming ' plan ie.
first daughter named after mother's mother - Marion Inglis Crawford
second daughter named after father's mother - Susan McLean Crawford
that would make me wonder if there was an earlier son to Janet Hamilton.
First son?? after father's father -
Robert CrawfordSecond son ?? after mother's father - Thomas Hamilton Crawford
Again I'm adding 2+2 and making 10
but this would make sense if Robert was lost on the SS Sicilia with a son (poor wee soul) as the newspapers suggest. Also having a young surviving child would perhaps explain how Robert came to marry his sister-in-law.
I'm not sure where you could look for Robert's death cert or when it would be issued (maybe they never found his remains ). Looking for an obituary might help. Or a burial/ memorial headstone possibly at Pembroke ? There are other articles btw. regarding the loss of the SS Sicilia in the Greenock Telegraph and Clyde Shipping Gazette but these are pay to view on British Newspaper Archive and may not give you any more on the disaster that you already have.
As for chasing up Robert in Ayrshire - Is his mother recorded as alive on his first marriage cert?
If she is not down as deceased it may mean she was still alive and therefore there should be a death certificate for her.
Good luck,
Looby
PS. Added - my last paragraph reads like nonsense
What I mean is if Susan Crawford nee McLean was still alive in 1858 when her son marries it means, unless she moved away from Scotland, there should be at a later date (sometime after Nov 1858) a Death Cert for her on SP. Phew !