Manufacturers throw out, literally, tons of usable and un-usable bike parts that are considered obsolete or blemished.  Since they have distributors / shops that buy and sell those parts, it makes little business sense to give them to a non-profit and potentially risk them being re-sold, warrantied a second time, or something else that might upset a paying distributor / shop.

The question is, is there much risk if the parts are re-purposed (think Resource Revival) into things like Art.  SRAM is trying it out, you might want to cite this example and hit up your local manufacturers or their distribution centers...