Buck Chuck Adapter Back Plate for 6" Diam Self Centering Lathe Chucks 4° Taper Mount, 1.32" Through Hole Diam, 4.906mm ID, 6-1/2" OD, 1.12" Flange Height, Steel A6-4DEG - 07013352 - Penn
CME 8" 3-Jaw Self-Centering (Scroll) Lathe Chuck with L00 Long Taper Backing Plate, Two-Piece Reversible Jaws - Amazon.com
Bison Adapter Back Plate for 5" Diam Self Centering Lathe Chucks 1-1/2 - 8 Mount, 1.515" Through Hole Diam, 2.164mm ID, 5" OD, 0.51" Flange Height, Steel 7-876-052 - 08610958 - Penn Tool Co., Inc
Lathe Chuck Face Plate, Easy to Install Steel Lathe Face Plate, Flat Cutting with 6 Mounting Holes for Industrial Use (14mm): Amazon.com: Tools & Home Improvement
MOUNTING ADAPTER PLATES ON SHORT TAPER SPINDLE NOSES DIN 55026 FOR LATHE CHUCK MOUNTING
a) Metal Lathe Chuck Backing Mounting Plate 1" ~ 10 TPI | eBay