Hi Alison,
First of all I am going to apologies as what I have to say might be a 'red herring' or of no use at all, but just sometimes odd bits of seemingly unrelated information strikes the right note, and I have the family connection of Fife, Tyneside and Laing ships.
My Great, great grandfather was Thomas Berry who had an older brother John Berry and they were both Merchant Seamen. John was born c1829 and Thomas was born c1838 in [Methil] Wemyss, Fife, just along the coast from Pittenweem, but I am struggling to find a record of their birth as there seems to be some big gaps in the Fife records! Shortly after the 1851 census they had moved from Fife having succumbed to the charms of Tyneside lasses, as John married Mary Jane Trentham in St. Hilda's, South Shields 17.1.1853, and Thomas married Catherine Barnes in Holy Trinity, South Shields 18.1.1859.
Now for the bit where the name Laing enters! My great, great grandfather Thomas Berry made a scale model of the sailing ship "Samuel Laing", and I am guessing here, but I think it was the ship on which he sailed. I can remember looking at it as a child, and even then I was in wonder at the detail it contained. It was housed in a glass case and he had even painted the background showing the entrance to the Tyne with Tynemouth Priory. However there were no Tynemouth or South Shields piers so the ship and painting must have been completed in the 1800's before the piers were built. Unfortunately it is no longer in the family as my Mam sold it to a 'Knocker' and regretted it for ever more. However I do have just a hint of what it looked like on a photograph which was taken on my great grandmother's 88th birthday, (Thomas's daughter Ellen) and although I loved her to bits I would just like her to step aside a few inches so I could see more of the ship! If you look at the picture you will see what I mean!
If anyone knows where the 'Samuel Laing' might be now I would love to know, as it seems a shame the history is no longer attached to it.
As I said at the start this might have nothing to do with the people you are searching for, but it is another connection between Fife and the North East of England.
Good Luck with your searching,
Patsy