Great idea and timely. I semi-followed that recent thread about some C&V frames gathering dust and scratches in a coop, or that's what it should have been about, before poor communication derailed it.
I only recently got back into riding and in the process, ended up donating two 90s Trek MTBs to our local coop, which I actually had to look up first. The Bike Connector in Lowell. Great place and I would like to volunteer, but at this time they only have limited hours on two weekdays and that just doesn't work with my job. I was allowed to explore the back of the shop which, after only two years in existence (even less than that at the current location), is already crammed full of steel road bikes that are difficult to find new homes for. I gather it's pretty much the same everywhere. I could see myself presenting a few of those here on BF every now and then, maybe maintain a BF account for the coop, that sort of thing. Right now it seems the coop only has time for putting the occasional really nice donation on Facebook.
One problem seems to be forum rules about what constitutes a for-sale offer. I think this would need to get clarified by forum management.