The black lion specialist used to carry a tab to trade these in, they no longer have the option to do so and no one accepts these tickets as far as I know.
Did you have the Golden Fortune in your inventory when speaking to the Black Lion Weapons Specialist? Have you tried the ‘Use’ function to bring up the Fortune Scrap Vendor?
http://wiki.guildwars2.com/wiki/Golden_Fortune_Scrap
Good luck.
Sonder the Seller has a tab for them now.
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