Roller lifters question
 

Here are some old small block Ford roller lifters that belong to an old friend. I've never seen any like these. He doesn't remember where he got them but they look pretty special to me. They are very light, a magnet does not stick to them, so they are either aluminum or titanium. Does anyone have a clue who made these lifters? Any information would be appreciated.
https://cimg7.ibsrv.net/gimg/www.for...4ce89f621f.jpg


https://cimg8.ibsrv.net/gimg/www.for...450db92c20.jpg


https://cimg9.ibsrv.net/gimg/www.for...db0b2897e5.jpg


https://cimg0.ibsrv.net/gimg/www.for...4172661a3c.jpg