The grand-grand son of the founder of the Swan factory was so kind to write me this history (Patrick thank you!):
The first Swan company was created by Eugène Seeuws.
He had 2 sons, Emeric and Nestor. The first one leaved the company before World W ar II. Nestor had a son, Jacques.
The company stopped in 1958, because of theft of big part of the working capital by one of the employees who wet out to south America with the money!
My father Jacques died without giving us more explanation.
I don't know who and why Triang, Swan and Torck made copies one of each other, but what i'm sure is that there where very much friendly contacts
between Torck, Seeuws and Beeusaert families. Hoping this little text can help you...