Hi Dandylion,
I don't know if this will help you, but I too was searching for an ancestor, living in Newburgh around this time, who disappeared. My search is here on rootschat:
http://www.rootschat.com/forum/index.php/topic,444235.0.htmlLong story short: I discovered that my 4xgt (changed from 3) grandfather perished in a boat made in Newburgh, with a crew from the town, in a storm off Sweden in 1860. Its loss was reported in the Glasgow Herald on Friday, November 16, 1860:
"Scotland - Loss of a Newburgh Schooner. - Intelligence has been received in Newburgh of the loss of the schooner Lady of Mugdrum, belonging to that port. She sailed from Elsinore on the 18th of October, laden with wheat, on her voyage from St. Petersburg to London. On the 22d of the same month she was discovered on the Swedish coast a total wreck. It is feared that the captain and the crew - most of whom belong to Newburgh - have been lost. The schooner was comparatively new."
James Whittet, my ancestor, was the Ship's Captain. It may be a very long, long shot, but perhaps your ancestor may have been on this voyage, too.
Best wishes, Jimmijam