Mystery Chuck/Jaw Set? PIC

[Steve Mathews]

While straightening out my barn/shop I came across the chuck and jaw set shown below. Anyone know what this is and its best use?
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[Barry McFadden]

Looks like part of the one I have..it's a Robert Sorby dovetail , screw, pin, chuck that I don't use anymore since I got the Oneway Chuck...

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[Wally Wenzel]

That is a PCC or precision combination chuck .My first chuck was one of those. Made in the UK, it worked but our scroll chucks of today are much better. Wallya

[Don Bunce]

https://drive.google.com/file/d/0B37nyVVAdcDnYkNNS1pWeHBHVXc/edit I had one of those many years ago. When the scroll chucks came out these became obsolete. A friend offered to trade his Nova chuck for my Precision chuck. The deal was done before he had a chance to change his mind. Still using the Nova chuck, never had a moment of regret for trading.

Here is a pdf of the maual for the Precision Combination Chuck.

[Barry McFadden]

It's annoying when the OP asks what this is and gets replies of exactly what it is but never checks back to acknowledge the replies.....why bother asking?