EDIT: Generously settled by Thalin: https://www.gog.com/forum/general/gogs_general_trading_thread/post2314
Thanks to everyone who tried to oblige. Want:
Dawn of War Master Collection Have:
(only Steam, sorry) Tropico 4 CE (gift), Mark of the Ninja, FTL, other keys, and a great willingness to accommodate!
If you have the key, even if you don't see something of interest, contact me and I'll do some backflips to satisfy you :-)