Did some eBay digging for you, there is a listing for a new PBA Setrite 6" three jaw scroll chuck, this is the same one that I use and they are made in the UK. Make an offer of something like $400 for a new in the box PBA. You will need ot purchase a PBA Setrite D1-4 back plate. The PBA Setrite D1-4 backplate (adapter plate) is 0605021. You will need to check around on pricing, the picture at the Grizzly site is not representative of the actual one. I would call around to small tools or Ajax to check pricing but expect they are around $300.
3 Jaws Self Centering Manual Lathe Chuck. Reversible Jaws Reversible Jaws. Jaw Type Master Jaws. Number of Jaws 3. Number of Jaw Pieces Two-Piece. Chuck Type Self-Centering. Nominal Chuck Size 6. Mount Plain Back.
www.ebay.com
These mounting plates are precision-machined to fit the spindle nose on your lathe. For maximum accuracy, mount the plate on the machine spindle nose, place a dial indicator on the chuck side face of the adapter close to the mounting holes, rotate the adapter and if the total indicator reading...
www.grizzly.com
This is what they list at which is close to 1K:
This is the 6" PBA Setrite on my lathe:
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