Okay...I'm not exactly sure how this works but I'll give it a try (let me know if I'm doing it wrong)
I'll take the White Chinese and Sebbie eggs and offer 2 American Buff goose eggs and 2 Silver Appleyard duck eggs.
A note about the buff eggs- I'll send three eggs because there is a slight chance that one is from my sebbie goose (fertilized by a buff gander) so one may not be purebred.
I guess I ought to ask, before taking any offers, if the khaki call duck hen with a blue call drake is aceptable here - both are calls, but not both the same color.
I have eggs "brewing" from them now, so I can take pics at some point (if they actually hatch - all of them so far have been fertile, but I hear call ducks are hard to hatch) so everyone can know what they might get out of them.