Material is 96% lead, 4% antimony; 4 counterbore holes at each corner, 1.125 center from side edge, 1.625 center from end.
No other part numbers with same form, fit, and function found.
NSN 6610-01-160-8815
NSN 5999-00-400-3099
NSN 5965-01-168-3255
NSN 5960-01-536-6398
NSN 5910-00-937-1329
NSN 6105-01-014-7570
NSN 5960-01-541-9884
NSN 5920-01-438-3640
NSN 5855-00-014-5008
NSN 6650-00-482-8984
NSN 5910-01-371-2553
NSN 5835-01-158-6878