Take this for what its worth, given that the only way I could participate is if you opened it up to those who add toning to their silver gelatin workflow.
One option that makes participation manageable is to have a limited number print exchange.
Something like each person agrees to send up to four prints.
Then just ask George Nova Scotia to send you a copy of the software (designed for the Postcard Exchange) he inherited to do the job of semi-randomly determining the lists of names and mailing addresses for everybody, with the quantity choice set to 4.
That way as many people as may be interested could commit without having to worry about being faced with suddenly being required to make and, almost more importantly, buy postage and mail more prints than they wanted to.
Heck, I could probably help with the software work, even without receiving a print (although I wouldn't say no

).