Okay
this auction would be great BUT it would depend on you in the sense of:
Are you willing to take a loss for charity? Consider your time, materials used and purchased to make the plaque - which, would run into $$$ from what you say.
If you do this for YDC 99 what about YDC 100, 101 etc?
I'll put this another way Al. I donated all my gift stock to YDC and I'm making a loss on it BUT I am pleased to help the charity concerned no matter what. I just cannot afford to cover the postage and fee costs too, so you might want to take that into account as well.
With the UK's RM making a massive hike in postage costs, especially internationally, they are doing an injustice for Charity auctions.