There was a brand new one on ebay for a year or two I couldn't believe how long it was there for.
One thing worth mentioning I tried contacting autotech to see if they offer warranty repairs and they said they no longer do. I emailed quaife uk and nothing, no response so there's that to consider. I was going to have them check mine out since I know nothing of the history/abuse or how to test them.
My australian 9 bolt lsd in my camaro had a test lock one wheel and turn the other and if it was over 36 ft lbs of torque you were good from what I recall.
One thing I did do in case anyone buys this is I shimmed the diff a few thousandths tight. Gary morell the genius suggested to do so since the aluminum case expands more than the steel quaife. I trust what he types so I did it but I still have yet to install the trans. IIRC he found out a way to shim the transmission shafts to help keep them from blowing up in high hp blown cars. I think the cases were flexing and causing misalignment and shearing like they do on the GM t5s.