Tuck the derailleur away for tomorrow. It just might have considerable value, one day.
A year ago I could not give away a set of 27" alloy wheels with quick release hubs. In addition to the cost of the wheel set, I have to tack on a large shipping cost that can reach and slightly exceed $75.00 to some North American destinations. In the past few weeks, I have sold three 27" rim sets and one wheel set. This morning I got an order for a single 27" rim, or rim set, or complete wheel set. Shipping, in this order will be roughly $40.00.
So, the point I am making is what appears worthless, or worth little, just might change its colors soon, and be worth more, and someday, lots more.
As for the Tourney derailleur, I have a few tucked away and, at the moment, I doubt that I could give even one away. But tomorrow might be a different story.
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"98% of the bikes I buy are projects".