Months have passed and I should have looked at this thread before. I expect you have all found out all you need to know by now -

Onyway:

moarning is morning - the spelling reflects the Shetland tongue.

homin is homecoming time not gloaming or twilight - that is the simmer dim, and aah - how I miss it...
so Wendy, that line you refer to means that the time for expecting them home is drawing near

There were no survivors and the community dispersed who knows how or where- 'dem at's awa' means they have gone forever

" Traditionally the parish of Delting, in which Mossbank is found, had far more to do with the sea than it does today, with fishing the main source of income. And the area paid a heavy price for its fish. As you drive into Mossbank you seen on your left the impressive stone memorial to those killed in the Delting Disaster of 21 December 1900. Twenty-two fishermen lost their lives, and the memorial shows where they came from. Six of those killed came from Firth, of which almost nothing now remains on the opposite side of Firths Voe from Mossbank."